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Introduction & Disclaimer
What Size Pond Liner Do I Need ?
Important Formulas for Determining the Requirements of your Pond
- Actual Pond Volume
- Effective Pond Volume
- Allowance for Fish Stocking Level
- Calculate Total Head
- Tubing Flow Rates
- Waterfall Weir Rates
- How to Measure a Flow Rate
- Useful Conversions
- introduction
- Pump Selection for Circulation Purposes
- Small & Shallow Ponds (up to 250 gallons approx.)
- Waterfalls & Streams
- Introduction
- Types of Filters
- Filter Selection
- Small & Shallow Ponds (up to 250 gallons approx.)
- Plain Water Filtration – No Waterfall or Stream
- Waterfalls & Streams
- Introduction
- Using an In-Pond Filter
- Using an Above-Ground Filter
- Above-Ground Pressurized Filters
- Above-Ground Gravity Discharge Filters
Installation & Setup of In-Line Centrifugal Pumps
Bylaws & Safety
Location
Materials
Pond Design Considerations
Edge Design Considerations
Tools Required
Pond Installation
Pond Maintenance
Algae & Blanketweed Control
Overwintering
The following material is provided as a service to our customers, for the purpose of sharing our knowledge of ponds and water gardens with other enthusiasts. We recommend that you treat this material as a guideline and general information only and obtain paid professional advice to look at your individual circumstances and evaluate whether the material presented on this website is accurate and applicable to your situation. All figures, guidelines, advice, performance specifications, etc. on this website are based on US gallons. If you can’t find the information you need, please send us an inquiry.
What Size Pond Liner Do I Need ?
Measure from a Plan
Length of liner required = Max. length of pond + (2 x max. depth of pond) + min. 2 feet (min. 60 cm) overlap
Width of liner required = Max. width of pond + (2 x max. depth of pond) + min. 2 feet (min. 60 cm) overlap
Measure off a Completed Excavation
If you are measuring off a completed excavation, use a flexible measuring tape or a rope that completely conforms to the contours of the excavation.
To determine the full length of liner required, run the tape or rope down into the pond, exactly following the contours of the excavation, across all the ledges, to the bottom of the pond, and back out the other side.
Then add at least 2 feet or 60 cm (minimum 1 foot or 30 cm per side) to allow for sufficient liner overlap outside of the pond.
Use the same method to determine the width of the liner.
Be sure to measure across the maximum length and width and at right angles to each other.
Example
Using one of the above formulas and including a minimum liner overlap of 2 feet (60 cm) for both length and width, you determine a required liner size of 23′ x 27′.
Now all you have to do is go to our pond liners page and look for a suitable size. In this case, the only suitable liner size is 25′ x 30′.
Important Formulas for Determining the Requirements of your Pond
Actual Pond Volume
Actual Pond Volume (US gallons)
= average length (ft) x average width (ft) x average depth (ft) x 7.48
Example
Pond is 12′ avg. length x 10′ avg. width x 2′ avg. depth
Pond Volume: 12 x 10 x 2 x 7.48 = 1,795 US gallons
Effective Pond Volume
When selecting the proper size equipment for your pond, actual volume alone is not enough. You must determine the effective volume of your pond which is influenced by various environmental factors. Determine if your pond is affected by direct exposure to sunlight, shallow depth, or climate conditions, and add to the actual volume by the factors listed below:
Average pond water depth is less than 2′ 6″: + 25 %
Pond is located in full sunshine: + 25 %
Pond is located in subtropical climate (e.g. Florida): + 35 %
Pond is located in temperate climate (e.g. Eastern Seaboard, Southern U.S.): + 15 %
Pond is located in Northern climate: + 0 %
Example 1
If you have a 1,500 gallon pond, 2′ deep and exposed to full sunshine in Kentucky, your pump and/or pond filtration equipment would need to be increased by 65 % (25 + 25 + 15).
You would therefore base your selection on a pond volume of 2,475 gallons.
Example 2
If you have a 2,500 gallon pond, 4′ deep, located in full sunshine and you live in a Northern climate, the effective volume of your pond is 3,125 gallons (2,500 + 25 %).
Allowance for Fish Stocking Level
The information listed above is based on a fish stocking level of not more than 100″ of fish per 1000 gallons of pond volume. Any variations in stocking level above this number will require a pro-rata increase in the size of all equipment. Thus, a 2000 gallon pond stocked at 150″ of fish per 1000 gallons will require equipment appropriate for a 3000 gallon pond, i.e. 50 % more fish requires 50 % greater equipment capacity.
Total Head
The higher the pump must push the water, the less water will be pumped. The terms “head” or “lift” are used to indicate the rise, measuring how high the water must be pumped for a particular application.
Pumping water through tubing (to a waterfall, for example) adds resistance. Please calculate friction loss as per the chart below.
Add the allowance for friction loss to the vertical distance (in feet) that you will be pumping the water. The vertical lift is measured from the surface of the pond. The resulting sum will be the TOTAL head that the pump will be required to pump. You should compare the amount of flow that you require to the flow rate that the pump provides at this specific head.
Example
Vertical distance between pond surface level and the top of the waterfall is 3 feet. You have 20 feet of tubing between the pump and the waterfall. Using a 3,200 GPH pump with 1-1/2″ tubing, your total head is approx. 5.4 feet (3 ft. + 2 x 14.4 in.). Using a 3,200 GPH pump with 2″ tubing, your total head is approx. 3.8 feet (3 ft. + 2 x 4.8 in.).
Tubing Flow Rates
The tubing size running from the pump is determined by the maximum flow rate of the pump you select. Pick the tubing diameter that is most appropriate for the volume of water coming from the pump. A hose adapter or a combination of adapters is required to attach the hose to most pumps. Following are the maximum flow rates in GPH for various tubing diameters:
| Max Flow (GPH) | |
| 300 | 1/2″ |
| 720 | 3/4″ |
| 1200 | 1″ |
| 3000 | 1-1/2″ |
| 4800 | 2″ |
Hint: If your pump does not deliver the amount of water it is rated for, perhaps you are using the wrong size tubing. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. The requirements of different pumps can vary and the above chart is meant as a guideline only.
Waterfall Weir Rates
When operating a waterfall, an important consideration is appearance. The volume of water required to achieve different effects (a robust waterfall or just a trickle) will depend upon the width of the waterfall lip (weir) or stream and the material that it is constructed from. The chart below will tell you how much water is required PER inch of waterfall width to achieve different thicknesses of water over the entire width of the waterfall weir. Once you have calculated the total head of the waterfall, it becomes quite easy to determine which pump to use.
| DesiredWater Thickness Sharp Metal Weir | DesiredWater Thickness Stone Weir 6″ to 11″ wide | DesiredWater Thickness Stone Weir 12″ or wider | Required GPH per inch waterfall width |
| 1/4″ | 3/16″ | 1/8″ | 30 |
| 3/8″ | 5/16″ | 1/4″ | 50 |
| 1/2″ | 3/8″ | 5/16″ | 75 |
| 3/4″ | 9/16″ | 7/16″ | 140 |
| 1″ | 3/4″ | 5/8″ | 200 |
| 1-1/4″ | 1″ | 3/4″ | 275 |
| 1-1/2″ | 1-1/4″ | 1″ | 375 |
Example
You have a 3′ tall (above the surface of the pond) waterfall and will have 15′ of tubing run between the pump and the top of the waterfall. The total head is thus 4.5′. To achieve a 3/4″ water thickness over the width of an 8″ wide stone waterfall weir, you would require a pump that would produce 1600 GPH (200 GPH per inch x 8 inches total width) at a total head of 4.5′. You can also use this chart to predict the effect that you will get from different volumes of water. Example If you use the same 3′ tall and 8″ wide waterfall as above with 15′ tubing run and you have a pump that only supplies 500 GPH at 4.5′ total head, you would expect to get 62.5 GPH per inch (500 divided by 8) over the 8″ width of the waterfall weir. This would result in a little less than a 3/8″ water thickness.
How to Measure a Flow Rate
This formula can be used to measure the flow rate of your pump.
Take a container of known volume (i.e. a 5-gallon bucket) and time how long it takes to fill it (in seconds) at the flow that you have. Then divide 3600 by the number of seconds it takes to fill the container and multiply by the volume (gallons) of the container. The result will be the flow rate in gallons per hour.
Example: It takes 10 seconds to fill a 5-gallon bucket. 3600 : 10 seconds x 5 gallons = 1,800 GPH
You can also use this formula to decide how much flow you would like over a waterfall. Simply place a garden hose at the top of the waterfall and adjust the volume of water until you find the flow that you like. Measure this flow and you will have an idea of the volume required to get the effect you desire.
Useful Conversions
You may find the following helpful:
To calculate power consumption: Volts x Amps = Watts
To calculate yearly cost of operation: Watts divided by 1000 x the price of electricity in $ per kilowatt hour x 24 hours x 365 days
One US gallon = approx. 0.834 Imperial gallons One US gallon = approx. 3.78 litres
One Imperial gallon = approx. 1.20 US gallons
In most cases the flow rates for pumps in North America are given in US gallons
How to Select A Pump
Introduction
From the smallest barrel garden to the largest koi pond, no water garden can survive very long without water movement. And for water movement, a pump is essential because it keeps the water circulating and the pond healthy.
A cascading, bubbling stream adds interest and serenity to the garden, while a waterfall can create a dramatic centerpiece. Fountains, while aesthetically pleasing, provide the additional benefit of aerating the water, essential for providing a healthy environment for fish. Water must also be supplied to filters that help keep the water clear.
Our website includes a large assortment of submersible pumps from manufacturers like AQUASCAPE, CAL PUMP, HOZELOCK CYPRIO, OASE, PONDMASTER, TSURUMI, and many more.
When selecting a pump, be sure to look for the GPH for each head height, as well as the maximum height that the unit will pump. At maximum height (or max. head), the pump only puts out a trickle of water. A long-term manufacturer’s warranty and energy consumption are also important factors.
Pump Selection for Circulation Purposes
To maintain a healthy pond, experts recommend circulating the water at least once every two hours. This means that for a pond with an effective volume of 3000 gallons, you will need to circulate at least 1500 gallons per hour (GPH). Hence, a pump capable of pumping 1500 GPH or more at the total head of your project is required. This is the absolute minimum amount of water that you need to circulate.
Small & Shallow Ponds (up to 250 gallons approx.)
Due to the special requirements and unique circumstances found in smaller and shallow ponds, including most pre-formed units, we recommend to turn the effective pond volume over once per hour. Example If the effective volume of your pond is 150 gallons, look for a pump that can deliver 150 GPH at your total head. If you are pumping up to a small waterfall or cascade 2 feet above pond surface level, you need to pump 150 GPH at a 2 foot head.
Also see Waterfalls & Streams below for additional information.
Sizing a pump for a waterfall or a stream is usually quite simple. The first item to consider is to ensure that you are circulating the effective pond volume at least once every two hours. This would be the minimum flow requirement. The second and usually the most important factor to consider is the characteristics of the waterfall. This includes the amount of flow that you wish to see coming over the waterfall and the width of the waterfall.
Please take a moment to review how to calculate the total head requirements for your waterfall.
Example
Assuming you want to operate a waterfall with a vertical head of 3 feet (vertical distance from pond surface level to top of waterfall) and you will have 10 feet of tubing between the pump and the top of the waterfall. You will have a total head of 4 feet. The smallest pump that you should consider would be one that is capable of circulating half the effective volume of the pond at a total head of 4 feet. Assuming an effective pond volume of 3,000 gallons, the pump that you choose will have to be able to deliver 1,500 GPH at a 4 foot head. This is the minimum requirement for circulation purposes.
Hint: Place your pump as far away from the waterfall as possible to maximize circulation within the pond.
When operating a waterfall, another important consideration is appearance. Depending on the width of the waterfall lip (weir) or stream and your expectations, half the effective volume may or may not be adequate.
The next step is to determine the flow requirements of your waterfall to achieve the type of effect you desire. You may need to consult the waterfall weir chart for more details.
Hint: As a rule of thumb, 100 GPH per inch of waterfall/stream width will provide a good flow equal to a sheet of water approx. 3/8″ thick over a stone waterfall weir 12″ or wider.
Example
Assuming the waterfall is 18″ wide and using the 100 GPH per inch guideline, you should select a pump that can deliver 1,800 GPH (100 GPH x 18″ width) at a 4 foot head (as calculated above). This is slightly more than the 1,500 GPH that the 3,000 gallon pond in our example requires for circulation purposes alone but will result in a more aesthetically pleasing display. Within reason, circulating the effective volume of the pond more frequently will not harm the pond.
Once you have determined the volume of water that you will require, go to our main pumps page and select an appropriate pump. In this case, you would look for a pump in the 2000 GPH max. output range because you require 1800 GPH at a 4 foot total head.
A suitable selection for our example would be a Supreme Pondmaster 2400. The final selection is up to you. Criteria would be initial cost, power consumption, and manufacturer’s warranty. The yearly operating cost comparison figures on the website make it easy to determine which pump will be most economical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will end up costing you more in the end.
If you would like to see a higher amount of water pumped over your waterfall, simply multiply the required GPH x the width of your waterfall in inches (see waterfall weir chart). For example, a 3/4″ thick sheet of water over a 12″ wide waterfall will require a pump that can deliver 3,300 GPH at the total head of your waterfall (275 GPH x 12″ width). If your waterfall is 18″ wide, your pump would have to deliver 4,950 GPH (275 GPH x 18″ width) to get the same 3/4″ water coverage. As you can see, the wider the waterfall, the greater the volume of water that is required.
Hint: Make sure your lower pond is sized in relation to your waterfall and the pump’s output. This helps ensure an adequate water supply for the pump at all times and helps contain any splash that the waterfall may cause.
If half the effective pond volume once every 2 hours is too much flow for your waterfall, we recommend to split the flow coming from the pump discharge by using a hose tee and diverting part of the flow to another water feature or to the other side of the pond to maximize circulation. You may have to install a ball valve in one or both of the lines to control the amount of water going in each direction.
All that is left to do is to choose the correct size of tubing as dictated by the maximum flow rate of the pump you select. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. As each pump has different requirements, the tubing flow rate chart is meant as a guideline only.
If the pump you are using is not listed on our website, you may want to consult the tubing flow rate chart to determine which size is most appropriate for the pump.
A hose adapter or a combination of adapters may be required to connect the tubing to most pumps.
Hint: If your pump does not deliver the amount of water it is rated for, perhaps you are using the wrong size tubing.
Skimmers are designed to remove debris floating on the pond surface. The skimmer is only effective as long as the debris is still floating. All skimmers have a debris collection system inside that will have to be emptied occasionally. The frequency of which will depend upon the amount of floating debris in the pond. It is critical that the debris be removed from the filter basket, mat or net when necessary so that water flow through the skimmer (and into the pump) is not impeded.
There are two basic types of skimmers. One is an out-of-pond unit. These units are made in various sizes that are suitable for a wide variety of ponds. They are best installed during initial installation of the pond liner. They are large units that are placed with the skimmer mouth at the surface of the pond. The pond liner is secured to the face of the skimmer and a hole is cut in the liner so water can enter the skimmer. Due to the fact they are attached to the liner, this type of skimmer is best installed into new pond construction. They have the advantage of being located outside of the pond at the pond edge. Many come with a decorative cover or can be covered so that they blend into the surrounding landscape. The fact that they are outside of the pond makes maintenance relatively easy. This type of skimmer usually has a submersible pump placed inside of it. The pump is protected from clogging by the debris collection system. It is critical that the debris be removed from the skimmer so that it does not impede water flow into the pump. The fact that the pump is not submersed in the pond makes access to the pump relatively easy. It is best to place the skimmer at the pond edge in a location where it is away from where the water from the pump will be re-entering the pond. The idea is to set up a circulation pattern between the skimmer intake and the pump discharge, be it an upflow filter, waterfall, stream, etc.
The second type of skimmer is an in-pond unit. They tend to be made for smaller ponds and you will have to find a way to empty the debris basket which may require you to wade into the pond quite frequently. This type of skimmer usually has a pump incorporated into it or is hooked with a hose to the intake of a suitable pump. It is critical that the debris collection system be maintained so that the flow of water into the pump is not restricted. This type of skimmer can be installed at any time.
Skimmers are sized for both the surface area of the pond they will be skimming and for maximum flow rate through the skimmer. When selecting a skimmer, you will have to consider the requirements of the other equipment within the pond (i.e. filters) or the requirements of your waterfall. You have to choose the skimmer based upon the larger of these criteria.
Example 1
Your pond has a surface area of 130 square feet. You could use a Nursery Pro Microskim skimmer. It is rated for up to 150 square feet and requires a pump with a flow rate between 500-2000 GPH.
Example 2
Your pond has a surface area of 130 square feet and you have a 20 inch wide and 4 ft. tall waterfall across the pond that will require a flow rate of at least 3000 GPH at the top of the waterfall. Depending upon the pump chosen, you are looking at a pump with a maximum flow rate of close to 4000 GPH. You will need a skimmer like the Savio Livingponds Skimmerfilter that can handle this larger flow rate even though it is oversized for the surface area of your pond.
It will also depend upon if you are installing the filter into an existing pond or if the skimmer is being installed into a pond while under construction. An in-pond skimmer is always the easiest choice for an existing pond.
The final selection criteria is if you want a skimmer with a UVC. At this time, only the Savio Livingponds Skimmerfilters have an optional UVC component that can be added to them. This is a good choice if you are thinking of having a UVC in your pond and the accessibility to an electrical outlet is a consideration (power is already near the skimmer because you need to supply the pump). In some cases, this may be an easier choice than purchasing a filter with a UVC, adding a UVC to an existing filter or adding a UVC inline between the skimmer and filter.
Maintaining a healthy pond environment with crystal clear water usually requires a filtration system. Filtration systems perform one or several of the following functions:
1) Mechanical Filtration – these trap particles in a material of some type for later removal during cleaning
2) Biological Filtration – these use beneficial bacteria to feed on impurities in the water; the bacteria break down fish wastes and other organic matter
3) Ultra-Violet Clarification – by exposing water to ultra-violet light, single-cell algae (waterborne algae) clump together for easier removal by a mechanical filter
Most filters for mid-size and large ponds employ a combination of mechanical filtration and biological filtration, and many can accommodate an ultra-violet clarifier as an option.
Depending on brand and model, the mechanical filtration can consist of layers of foam pads, trays of gravel, foam cartridges, or brushes. Some models combine several of these into one filter. In addition, many filters contain a chamber for plastic bio-media. These are specially designed plastic pieces 1 to 2 inches in diameter. One cubic foot of these pieces can contain as much as 84 square feet of surface area. This large surface area encourages the growth of beneficial bacteria colonies – the secret of effective biofiltration. Once the colony is established, it converts ammonia from fish waste, dead organic matter and other impurities into nitrites and later into harmless nitrates and nitrogen which help promote the growth of plants.
Without help, it can take up to seven weeks for a bacteria colony to take up residence and grow large enough to be effective in a typical biofilter. This process can be accelerated through the introduction of additional bacteria, available either in dry, granular or liquid form.
The rate of water flow through the biofilter will have a major effect on its effectiveness. All filters have a maximum flow rate. This flow rate must be observed. Slower flow rates may result in the volume of the pond not passing through the filter as often as it should for efficient filtration to occur. Faster water flow will not allow the bacteria enough time to clean the water completely and may even dislodge the bacteria from the media. Likewise, care should be taken when cleaning a biofilter. Mechanical elements (filter foam) should be rinsed in a separate container of pond water. If the filter contains more than one layer of filter foam, clean them in rotation. The biomedia should not be disturbed to enable the beneficial bacteria to remain.
There are a number of different filter designs.
a) In-Pond Filters: These small filters usually fit on the intake of the pump or around the pump itself and allow you to run a fountain head or waterfall off the pump’s discharge. They are usually only used in smaller ponds and tend to me more difficult to maintain because they have to be removed from the pond for cleaning.
An in-pond filter is not to be confused with a pump pre-filter. Pump pre-filters are usually small foam filters designed to protect the pump from large particles that may cause it to clog up. Pump pre-filters are not designed to filter the pond water. Supreme Pondmaster PM1000 In-Pond Filter
b) Above-Ground Filters: There are two main types of above-ground filters. Pressurized and gravity-discharge. Above ground filters are easier to perform routine maintenance on because they are already out of the pond. Pressurized filters (such as Cyprio Bioforce Series) allow you to filter the water and discharge it under pressure to the top of a waterfall. The amount of lift that can be achieved after the filter discharge is limited and should be restricted to a couple of feet. This type of filter is fairly easy to camouflage. It can be hidden behind a shrub or, in the case of the Cyprio Bioforce models, they can be buried in the surrounding area up to the level of the lid. Gravity-discharge filters (such as most other styles of above-ground filters) must be placed so that the water discharges freely by gravity only. To operate a waterfall or stream with a gravity-discharge filter, it must be situated at the highest elevation, with the discharge pipe feeding the waterfall/stream by gravity. These filters are for above ground use only and are usually set at the edge of the pond.
All models are available in a wide range of sizes to accommodate most sizes of ponds.
Please calculate the actual pond volume and use this figure to calculate the effective volume of your pond. Add in an allowance for fish stocking levels if necessary.
All filters have a maximum pond volume that they are rated for. You have to choose a filter that is rated for the effective volume of your pond (with an allowance for fish stocking levels if applicable).
Small & Shallow Ponds (up to 250 gallons approx.)
Due to the special requirements and unique circumstances found in small and shallow ponds, including most pre-formed units, we recommend to use a pond filter that is rated for double the effective pond volume.
Example
If the effective volume of your pond is 150 gallons, look for a filter that is rated for ponds up to 300 gallons.
Plain Water Filtration – No Waterfall or Stream
This is filtration at its simplest. All you require is a pond filter/pump combination that is rated for the effective volume (plus an allowance for fish stocking level, if applicable) of your pond.
You would start by selecting a pond filter that has a maximum pond volume rating greater than the effective volume of your pond. Go to our main pond filters page and have a look at our selection. Pick any filter that is sized correctly and suits your particular setup, in-pond or above-ground.
If an in-pond filter is the most suitable, all you have to do is place it in the pond and plug it in. Most of these filters have a pump included with them and many come with small fountain heads. If you add a short piece of tubing, many can be used to operate a small waterfall or spitter.
If an above-ground filter is the most suitable, the type you choose will depend upon the effective volume of the pond as well as the type of installation that you have planned. Above-ground filters do not include a pump which must be purchased separately.
Hint: When you are sizing the pump, remember to place the pump as far away from the filter discharge as possible. This will maximize water circulation within the pond.
Each filter has a maximum flow rate listed for it. This is the maximum amount of water that the pump can supply to the filter. If you exceed this amount, the filter will not work as efficiently, it might overflow and you may damage the filter unit. You will have to calculate the total head to the filter intake. Once you have calculated the total head to the intake of the filter, go to our main pumps page and select an appropriate pump based on the required flow rate at the total head at the filter intake. Pick a pump that will deliver close to but does not exceed the flow rate that the filter requires. The final selection is up to you. Criteria would be initial cost, power consumption, and manufacturer’s warranty. The yearly operating cost comparison figures on the website make it easy to determine which pump will be most economical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will end up costing you more in the end.
Hint: For filtration purposes, rather than using a pump with an integrated foam pre-filter, we recommend to use a pump that comes with a screen housing. The foam pre-filters clog up quite easily and require a lot of maintenance. On some pumps, like the Nursery Pro Mag Drive, 250 GPH and larger models, the foam pre-filter can be replaced with a mesh filter screen (Nursery Pro NP-218FS).
The tubing size running from the pump to the pond filter is determined by the maximum flow rate of the pump you select, as well as the intake fitting size of the pond filter. Most pond filters feature step-down hose tails which allow attaching several different tubing diameters, for example from 3/4″ to 1-1/2″. Filter intake fitting sizes are shown for each filter. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. Pick the tubing diameter that is most appropriate for the filter and the pump. If you can not find a listing for your pump, you can also use the tubing flow rate chart to determine the correct tubing (please remember to ensure that it will fit on the filter intake). A hose adapter or a combination of adapters may be required to attach the tubing between the pump and the filter.
Introduction Choosing a filter to use in combination with a waterfall or stream can be a little more complicated but, again, all you require is a pond filter/pump combination that is rated for the effective volume (plus an allowance for fish stocking levels, if applicable) of your pond.
Select the pond filter that is rated for the effective pond volume that you have. Go to our main pond filters page and have a look at our selection. Pick any filter that suits your particular setup, in-pond or above-ground. You will also need to determine the flow requirements for your waterfall. The volume required will be based upon the effect that you wish to see and the width of the waterfall that you have constructed. Please go to the How to Select a Pump/Waterfalls & Streams section to calculate your flow requirements. You will need this figure later on in the calculations.
Using an In-Pond Filter Please take a moment to review the introduction above where sizing requirements and filter selection are covered. All of the information contained hereafter is based upon this.
If you have a small pond and waterfall and the in-pond filters are the most suitable, all you really have to be concerned with is the expected flow rate down the waterfall. Since most of these filters have a pump included with them, have a look at the flow rates for the pump that the filter is supplied with. Does the pump/filter flow rate correspond to the volume requirements that you calculated ? If you have more flow than you require, many of these filters also come with small fountain heads. If the waterfall will be very small, it may be possible to have both a fountain display and a small waterfall. If the flow is just adequate, you will likely have to replace the fountain heads with a short piece of tubing and operate only the waterfall. If the amount of flow is not adequate, you may want to get a separate pump to supplement the flow of water down the waterfall.
An above ground filter is usually the most suitable due to maintenance concerns, design of the pond and/or the effective volume of the pond. Above ground filters do not come with a pump. Sizing the pump will depend upon whether you wish to operate the filter and waterfall with only one pump or if you will use separate pumps for the two items. If you are using separate pumps, you simply size a pump for each application. If you want to operate both items from one pump, this becomes much trickier.
There are two basic types of above-ground filters, pressurized and gravity discharge. If you choose a pressurized filter, you will have different things to consider than with a gravity discharge filter.
Above-Ground Pressurized Filters
Please take a moment to review the introduction to this section where sizing requirements and filter selection are covered. All of the information contained hereafter is based upon this. Even though the water coming out of the discharge of the pressurized filter is under pressure, the amount of vertical lift and the length of horizontal hose run after the filter discharge should be kept as small as possible. Even two feet of vertical lift and/or 10′ of tubing run after the filter discharge can decrease the flow rate a great deal. The best indication of what you can expect is in the performance rating for the pump that you have chosen to operate the pressurized filter.
Example
The Nursery Pro NPU1000 pump has a maximum flow rate of 1,000 GPH at a 1′ head. If you have 3′ vertical lift to the top of the waterfall and 20′ of total tubing run in the entire system, you would have a total head of 5′. If you operated the pump alone you could not expect more than 800 GPH. The same NPU1000 pump in combination with a Bioforce 2000 filter (maximum flow rate 1,000 GPH) installed at ground level and adjacent to the pond with 10′ of hose between the pump and the filter intake, another 10′ of hose attached to the filter discharge and a 3′ vertical lift to the top of the waterfall after the filter discharge, would result in an estimated flow rate of approx. 650 to 700 GPH. The lower flow rate is due to friction losses caused by the filtration process. As the filter becomes clogged the flow rate would continue to drop.
To avoid this, place the pressurized filter so that the majority of the hose run and the vertical lift is before the filter intake. This will enable you to use a slightly larger pump to provide as close to but not over the maximum flow rate for the filter. Using this system and the example above, and assuming that you were able to install the Bioforce 2000 filter at the top of the waterfall, you could use a pump that would supply the filter intake with up to 1,000 GPH at a head of 5′ and achieve a flow rate of approx. 900 GPH out of the filter (this will of course depend upon the pump that you choose).
Whichever setup you plan to use, calculate the total head at the intake of the filter and be sure to note the maximum flow rate for the filter you have chosen. Then go to our main pumps page and select an appropriate pump that will deliver close to but not over the flow rate that the filter you have chosen will require at whatever the total head is. The final selection is up to you. Criteria would be initial cost, power consumption, and manufacturer’s warranty. The yearly operating cost comparison figures on the website make it easy to determine which pump will be most economical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will end up costing you more in the end.
Hint: For filtration purposes, rather than using a pump with an integrated foam pre-filter, we recommend to use a pump that comes with a screen housing. The foam pre-filters clog up quite easily and require a lot of maintenance. On some pumps, like the Nursery Pro Mag Drive, 250 GPH and larger models, the foam pre-filter can be replaced with a mesh filter screen (Nursery Pro NP-218FS).
The last consideration would be the flow rate that you will be getting out of the end of the discharge hose coming from the filter/pump. Does this correspond to the flow rate requirements for your waterfall that you calculated previously ? If the volume coming out of the filter is not sufficient, you can either use a filter sized for a larger pond volume, get a separate pump to operate and/or supplement the flow of water coming down the waterfall, or use a larger pump and split the volume of water between the filter and the waterfall. Please click here for more details on how to do this.
The tubing size running from the pump to the pond filter is determined by the maximum flow rate of the pump you select, as well as the intake fitting size of the pond filter. Most pond filters feature step-down hose tails which allow attaching several different tubing diameters, for example from 3/4″ to 1-1/2″. Filter intake fitting sizes are shown for each filter. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. Pick the tubing diameter that is most appropriate for the filter and the pump. If you can not find a listing for your pump, you can also use the tubing flow rate chart to determine the correct tubing (please remember to ensure that it will fit on the filter intake). A hose adapter or a combination of adapters may be required to attach the tubing between the pump and the filter.
Above-Ground Gravity Discharge Filters
Please take a moment to review the introduction to this section where sizing requirements and filter selection are covered. All of the information contained hereafter is based upon this. Using a gravity discharge filter for this type of installation will have a few limitations. Since they are gravity discharge, they have to be situated at the top of the stream or within the waterfall so that the water can flow freely from the filter discharge. If you are able to overcome this, your waterfall will be limited to the amount of water that is flowing through the filter.
These filters do not include a pump. Now you have to find a pump that is suitable. As mentioned earlier, place the pump as far away from the waterfall as possible. This will maximize water circulation within the pond. Calculate the total head to the position where the filter intake will be located. Each type and size of filter has a maximum flow rate listed for it. This is the flow rate that you have to supply the filter with at the total head that you just calculated.
Now go to our main pumps page and select an appropriate pump that will deliver close to but not over the flow rate that the filter you have chosen will require at your total head. The final selection is up to you. Criteria would be initial cost, power consumption, and manufacturer’s warranty. The yearly operating cost comparison figures on the website make it easy to determine which pump will be most ecomomical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will end up costing you more in the end.
Hint: For filtration purposes, rather than using a pump with an integrated foam pre-filter, we recommend to use a pump that comes with a screen housing. The foam pre-filters clog up quite easily and require a lot of maintenance. On some pumps, like the Nursery Pro Mag Drive, 250 GPH and larger models, the foam pre-filter can be replaced with a mesh filter screen (Nursery Pro NP-218FS).
The tubing size running from the pump to the pond filter is determined by the maximum flow rate of the pump you select, as well as the intake fitting size of the pond filter. Most pond filters feature step-down hose tails which allow attaching several different tubing diameters, for example from 3/4″ to 1-1/2″. Filter intake fitting sizes are shown for each filter. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. Pick the tubing diameter that is most appropriate for the filter and the pump. If you can not find a listing for your pump, you can also use the tubing flow rate chart to determine the correct tubing (please remember to ensure that it will fit on the filter intake). A hose adapter or a combination of adapters may be required to attach the tubing betwwen the pump and the filter.
The amount of water that you put into the filter will be the flow rate that is available for your waterfall. You will, however, lose a little volume to the filtration process and the volume will decrease as the filter becomes clogged. Does the flow rate that you will be getting out of the filter correspond to the flow rate requirements for your waterfall that you calculated previously
At the beginning of this section we said that things can get a little more complicated when combining a pond filter with a waterfall. Why ? Because the amount of water coming out the discharge of the filter may not correspond with the amount of water you would like to see coming over your waterfall. It is possible that you will require more water coming down the waterfall than the filter is capable of supplying. If this is the case, all you can do is install a second pump to supplement the flow or use a pump that provides a larger flow rate than what is required for the filter. You will have to split the water coming from the pump discharge into two. One of the hoses would simply empty at the top of the waterfall. The water in the other hose would go through the filter and then make its way down the waterfall. You will likely have to install ball valves or some method of regulating the flow into one of the two lines to ensure that the maximum flow rate for the filter is not exceeded.
Adding a Ultra Violet Clarifier is a good idea if you have a significant amount of suspended algae in the pond. The UV light kills the algae and causes it to clump together. Once the algae is in clumps, it is easier for the filter to remove. Some UVCs can be submerged and some are only suitable for installation above ground. A UVC can be installed anywhere on the pressure side of the pump but the most suitable place is after the pump and before the filter. This way the filter can remove the algae. If the clumped algae is released back into the pond, it will settle out to the bottom.
Hint: To maintain peak efficiency, the UVC bulb should be replaced on a yearly basis even if it is not blown out. This is due to the fact that the UV bulb will burn less brightly over time.
Sizing the UVC is quite easy. All UVCs have a rating for the volume of water that they are recommended for and they all have a maximum flow rate. You can not exceed the maximum flow rate for the UVC. The suspended algae in the water needs to be exposed to the UV light for a sufficient period of time to cause the algae to clump together. If the flow rate is higher than recommended, the water will pass by the UV bulb too quickly for it to be effective. The higher flow rate could also damage the UVC unit. Other considerations are the flow rate requirements of the filter if you are powering the two items from one pump.
The UV Clarifiers do not include a pump. Now you have to find a pump or ensure that the pump you will be using is suitable. Calculate the total head to the position where the intake of the UVC will be located. Each type and size of UVC has a maximum flow rate listed for it. This is the maximum flow rate that you can supply the UVC with at the total head that you just calculated.
Now go to our main pumps page and select an appropriate pump that will deliver close to but not over the flow rate that the UVC you have chosen will require at your total head. The final selection is up to you. Criteria would be initial cost, power consumption, and manufacturer’s warranty. The yearly operating cost comparison figures on the website make it easy to determine which pump will be most ecomomical to operate over the long term. Sometimes, a less expensive pump with a high power consumption will end up costing you more in the end.
Hint: For the purpose of operating a UVC, rather than using a pump with an integrated foam pre-filter, we recommend to use a pump that comes with a screen housing. The foam pre-filters clog up quite easily and require a lot of maintenance. On some pumps, like the Nursery Pro Mag Drive, 250 GPH and larger models, the foam pre-filter can be replaced with a mesh filter screen (Nursery Pro NP-218FS).
The tubing size running from the pump to the UVC is determined by the maximum flow rate of the pump you select, as well as the intake and discharge fitting size of the UVC. Many UVCs feature step-down hose tails which allow attaching several different tubing diameters, for example from 3/4″ to 1-1/2″. These intake and discharge sizes are shown for each UVC. Recommended tubing sizes are listed for each pump that we sell. Please click on the pump model number for more details. Pick the tubing diameter that is most appropriate for the pump and will fit on the UVC. If you can not find a listing for your pump, you can also use the tubing flow rate chart to determine the correct tubing (please remember to ensure that it will fit on the intake and discharge of the UVC). A hose adapter or a combination of adapters may be required to connect the hose to most pumps and you may require adapters for the intake and discharge fitting of the UVC as well.
Installation & Setup of In-Line Centrifugal Pumps
Locate the pump as close to the source as possible. It is best to have your main (longest) run of pipe on the discharge side of the pump.
Flooded Suction
Install the pump outside the pond and below the surface level of the pond to create a flooded suction. This will help ensure a proper and consistent supply of water to the pump. The pump will not operate properly and may be damaged if the water supply is not constant. A flooded suction may be retained with a supply line that runs up over the pond wall and back down below the water surface, as long as all air has been removed from the line. DO NOT RUN THE PUMP DRY !
Non-Flooded Suction
If installation of a flooded suction is not possible, we recommend the following: Position the pump as low as possible and as near the source as possible. Install a priming pot on the pump inlet. Install a foot valve or a check valve in the inlet below the water level. Always prime the entire inlet line, priming pot, and pump before turning it on. DO NOT RUN THE PUMP DRY !
Before you consider installing a pond or any other water feature we recommend to consult your municipality’s Zoning Department for possible water depth restrictions, as well as fencing, and/or building permit requirements for your particular area. You can usually find a listing for the Zoning Department in the blue pages of your local telephone directory, sometimes under its own heading but usually under the Building, Engineering, or Planning Departments. If not, just call City Hall, and they will direct you to the appropriate department. This is a very important issue. Bylaws differ from city to city and may even be different from one block to the next. A five-foot deep fish pond in the front yard may not pose a problem in a rural setting but may well be a danger spot in a downtown location or next to your local elementary school.
The best approach is to first make a sketch of your property, showing the proposed location, shape, size and depth of your water feature. Then go down to City Hall in person, present your plan to the Zoning Department, and ask them to approve it in writing. This way, you have complete peace of mind knowing that your pond falls within your municipality’s guidelines and does not become a legal concern down the road.
Even if a bylaw does not exist in your community, use your common sense and exercise caution where children are involved.
Before you get the shovel out of the shed you might want to make a few more inquiries. Think of underground services like sewers, gas and power lines, cable TV, telephone, etc. Be safe and call before you dig.
Don’t forget to inform your insurance company about your new pond. They always like to know what’s going on in and around your property. If you plan to operate electrical equipment in your pond, such as a fountain pump or underwater lighting, make sure that you use approved equipment only and connect it to a properly grounded and GFCI (Ground Fault Circuit Interrupter) protected outlet only. Most outdoor receptacles on newer homes are already GFCI protected. When in doubt, ask your electrician for assistance.
Carefully read all instructions supplied before operating any equipment. Always follow the manufacturer’s recommendations and guidelines. Do not run extension cords across your lawn. Not only are they not approved for use around the pond but they will only get chewed up by your lawn mower, and you risk getting electrocuted.
The best placement for your water feature is the location that will provide you with the most pleasure. Your water feature should be close enough to be seen, heard and enjoyed. Water can produce a variety of sounds depending upon the layout of the feature. A gurgling brook, the light spray from a fountain head, the splashes from a bathing bird or the crash from a waterfall. Even if the pond is not immediately visible the sound will be there to relax, soothe and act as a drawing feature.
It is also important to consider your water feature from the perspective from inside your home. You probably spend more time inside your home than out in your yard, and if you have a view of the pond from the breakfast nook or your favorite reading chair you can enjoy its beauty at any time and might be privy to a lot of animal activity that you would otherwise miss.
This same idea goes for sound. Your neighbors may not share your views on this but perhaps your idea of heaven is being lulled to sleep by the croaking of frogs. Then, be sure to put the pond close enough to your bedroom window so you have a concert every night. If you don’t get along with your neighbors and plan to keep it that way you may want to consider moving the pond a little closer to their bedroom window.
Other determining factors are sunlight, the existing landscape and the elements within it, as well as accessibility of utilities.
Sunlight is very important for growing most water plants and also gives the pond a magical reflective quality. Sometimes a shady location is the only location available for your pond. Do, however, be warned that, if this shade is provided by trees, their falling leaves or needles will become an endless source of debris in your pond. A lot of decaying material is harmful to other life within your pond and should be removed on a regular basis. A little shade is fine but, ideally, for most gardening purposes your pond should have six or more hours of direct sunlight per day. If water lilies are your passion then, the more sun the better.
Another thing to consider is the existing landscape, its architectural style and size, as well as the elements within it. For example, a natural slope may work to your advantage as the basis for a waterfall, cascading steps or a meandering stream. Also consider the existing locations of trees, not only because of their leaves as previously mentioned but because their roots may cause a problem during excavation. They can be cut but you may harm the tree in the process.
The existing soil and site conditions are also very important. The pond should be situated on level terrain. This helps ensure a uniform water level around the entire circumference. Avoid the lowest point in the landscape because of potential run-off and drainage problems. A high water table or very rocky soil may make a raised water feature more feasible than an in-ground pond.
It goes without saying that the style of the water feature should be in harmony with the rest of the landscape and the buildings. A natural shaped pond edged in field stone will look out of place in a formal English rose garden. The size of the water feature must also harmonize with its surroundings. A very large water feature in a small residential yard will be out of scale as would a relatively tiny pond in the middle of a six-acre lot. The size of your pond is ultimately determined by its environment, its purpose, and the amount of money you are prepared to part with.
Is it meant to be the focal point of your yard or do you wish to place it discretely within the landscape where it will provide an element of surprise upon its discovery ? Is it meant mainly for gardening purposes or are you interested solely in the acoustical quality of the water ? The most successful water gardens are those that were thoroughly thought out and planned before the shovel and the wheelbarrow were ever removed from the shed.
Another important item to consider is the accessibility of both water and electricity. Your pond may need to be topped up from time to time and should be within easy reach of your garden hose, unless you are planning to incorporate an automatic filling system which will require some plumbing work.
Electricity is needed if you plan on using a recirculating pump or underwater lighting, for example. It is very important that the electrical receptacles be close to the pond (consult your electrician for current regulations regarding minimum distance requirements from electrical outlet to pond). Exposed power cords make an excellent snack for squirrels and raccoons, and, aside from having to replace a gnawed electrical cord, you may even have to deal with a damaged pump. Some cords use a paper wrapping around individual wires which absorbs water, acts as a wick and draws water right into your pump motor. Make sure that your receptacles are properly grounded and GFCI (Ground Fault Circuit Interrupter) protected. Contact your electrician for assistance. Exposed power cords are also dangerous when mowing lawns, and they can be tripped over. Extension cords are not a good idea around the pond.
The last consideration is wind. If you are planning a large spraying fountain, a fleur-de-lis, for example, and wind is a problem in your area, consider either lowering the height of the display or increasing the surface area of the pond. Unless you have an automatic top-up system it is crucial that the water returns to the pond and does not end up in your flower beds. You might want to think of a more sheltered location for a feature of this type.
You have several choices when it comes to selecting the proper materials for building a garden pond. The most popular and versatile waterproofing material is a flexible pond liner. It allows you to design the pond to your requirements and personal taste and gives you the option of completing the entire project by yourself without the need for a knowledgeable landscape contractor.
Flexible pond liners are made from PVC, EPDM, HDPE, BUTYL, etc. and range in thicknesses from 15 to 60 mil. The most popular and easy-to-work-with thickness is 35 to 45 mils. For small-scale projects on a limited budget you may be able to get away with thinner liners but, because they are more susceptible to tearing and puncturing, you have to be more careful.
Make sure that the liner you purchase is non-toxic. This is imperative for growing waterplants and keeping fish in your pond. Do some homework and select a pond liner with a proven track record and a good manufacturer’s warranty. Look for things like UV-resistance and non-toxicity, as well as resistance to extreme temperatures.
These features become extremely significant when the material cost and labor for the liner installation are put in relation to the overall cost of the entire project. Liner plus installation cost represent only a fraction of the investment in the completed project. However, if the liner has to be replaced due to a product failure, the above cost relation reverses. The replacement of a pond liner necessitates the removal of all components, such as edging materials, plants, fish, pumps and fountain equipment, and most importantly, a very smelly liner. For that reason alone it becomes imperative to select a product with a proven track record of trouble-free performance.
Do not use old swimming pool liners. They are bad news. Due to their color they look artificial which you may be able to live with but, over the years, they may have absorbed quite a bit of chlorine and other pool chemicals which could leach back into your pond and destroy all life within it.
Once you have selected a suitable pond liner you have to decide whether you can use a standard size liner or whether you have to get one custom made to fit your pond’s particular size and shape. Most companies offer several choices of standard sizes which are usually a little cheaper than a custom size and are also more readily available.
To figure out exactly what size of liner you will require you can either take the measurements off your plan or wait until you have the excavation completed.
Use the following formula to calculate your liner requirements from a plan: Length of liner required = Max. length of pond + (2 x max. depth of pond) + min. 2 feet (min. 60 cm) overlap Width of liner required = Max. width of pond + (2 x max. depth of pond) + min. 2 feet (min. 60 cm) overlap
If you are measuring off a completed excavation use a flexible measuring tape or a rope that completely conforms to the contours of the excavation. To determine the full length of liner required run the tape or rope down into the pond, exactly following the contours of the excavation, across all the ledges, to the bottom of the pond, and back out the other side. Then add at least 2 feet or 60 cm (min. 1 foot or 30 cm per side) to allow for sufficient liner overlap outside of the pond. Use the same method to determine the width of the liner. Be sure to measure across the maximum length and width and at right angles to each other.
Another very popular choice are pre-formed ponds. These are heavy-duty pools, usually made from high-density polyethylene, glassfiber reinforced polyester, fiberglass, etc. They stand up very well to the elements, are hard to destroy and come with a long-term manufacturer’s warranty. The installation can easily be accomplished by the average home owner.
Pre-formed ponds are, however, not nearly as versatile as flexible pond liners. Most of them are relatively small and usually have only one, maybe two, planting ledges. You have no input into the design, shape and depth and are limited to whatever is commercially available.
Another factor is cost. You will find that a flexible pond liner that covers the same area as the pre-formed pond is usually quite a bit cheaper.
The other two materials suitable for waterproofing a pond are clay and concrete. Most of us would require the help of a specialized contractor to apply any of the above, and they are therefore not the materials of choice for the do-it-yourselfer. In addition to a pond liner or pre-formed pond you will also need some sand and/or a non-rotting polyester felt to act as a cushion and protection layer between the liner and the soil underneath it. When using heavy boulders as edging materials or when placing heavy objects within the pond we recommend using heavy-duty rubber mats as a protection layer between the boulders and the pond liner. This is explained in more detail in the Installation section. Unless you plant them in a bog garden, water plants are best planted in pots. This facilitates future changes and moving them to other locations within the pond, as well as moving them to a deeper spot or indoors for overwintering. Contact a waterplant specialist or grower for advice on plants that thrive in your particular area and climate zone. You also need the proper edging materials to complement your pond’s appearance. Popular choices are river rocks, pebbles, patio slabs, irregular rocks and boulders, etc. Avoid anything with sharp or rough edges that could puncture the liner or provide a suitable protection layer of polyester felt or rubber mats. You can find more information on this subject in the Edge Design and Installation sections. You might also consider adding a submersible fountain pump with a spraying or bubbling fountain head, a pond filter or underwater lights.
The design of your pond will be determined by many factors, the most important of which are its surroundings and its purpose.
There are two basic design types, formal and informal.
A formal design is characterized by geometric shapes and is clearly man-made.
An informal design is free-form in shape and has the appearance of being part of the natural landscape.
Consider the architectural style of the surrounding buildings, as well as the existing landscape when selecting between a formal and informal design.
The edging materials you choose and the way you assemble them will also determine the design type. A border of loose and irregular field stone, grass or plants cascading and tumbling into the water will look informal, whereas paving stones or other permanently assembled materials help reinforce the geometric shape of a formal pond.
When it comes to determining the size of your pond, both the scale of the existing landscape and the pond’s desired use must be considered. Avid gardeners will no doubt require a larger surface area to accommodate a large variety of plants, whereas a less devoted gardener who only wants to have a waterlily and a few fish will not require that much space. Keep in mind that at least 60 to 75 % of the pond’s surface area should be covered by plant material.
The depth of the pond is almost solely determined by its purpose, taking into account safety considerations. Different varieties of water plants require different water depths. For example, a potted waterlily prefers to have 12 inches (30 cm) between the soil surface and the water line, whereas a bulrush prefers to have only its roots in water. If you wish to cultivate a variety of water plants then planting ledges at different depths should be incorporated within the pond. The pond should also provide enough depth so that plants and fish can be protected during winter’s cold.
Planting ledges have the added advantage of acting as access steps when you have to enter the pond for any reason. A pond with straight or sloped sides will be very dangerous to walk into plus the plant baskets or pots will have nowhere stable to sit. Even with several ledges in place you still have to be careful when entering or stepping out of the pond because the soil below may not be stable enough to support the weight of a person. Another thing to consider is the pond liner itself which will be very slippery.
A water garden can also be accommodated without expanses of open water, either because of safety concerns or by choice.
A bog garden is an ideal environment for moisture-loving plants and is very easy to construct. Simply dig out a 12 to 18 inch (30 to 45 cm) deep area, waterproof it with a pond liner, fill with soil and plant with reeds, rushes, ferns and irises. To support bog plants the soil should be moist at all times. Perhaps you already have a natural low lying wet spot in your garden. This might just be the solution.
The edging material you choose for your pond should be in harmony with the pond itself. An informal shaped pond in a natural setting surrounded by square pavers results in a conflicting effect. Instead, select irregular cut flag stone, river rock 4 to 6 inches in diameter or larger irregular stones and/or boulders. In short, use materials that appear in nature itself. You could even have a natural landscaped border of grass, wildflowers or moisture-loving plants around your pond. For formal pools choose man-made materials, for example symmetrical pavers, tiles, cut concrete blocks, etc. No matter what materials you decide to use, the main objective is to make sure that the pond liner, pre-formed pond or concrete is not visible above the water line. To accomplish this either blend the border into the edges of the pond or, when using pavers, overhang them over the edge of the pond.
Tools Required Now that you have found the perfect spot for your new pond and have determined the size and general shape of it you can start assembling some tools. Here is a list of what you will need:
- A rope, long enough to follow the entire outline of your pond,
- a wheelbarrow,
- a shovel,
- a spade,
- a pick axe (if you happen to have clay in your backyard),
- a flexible measuring tape,
- a level,
- a straight board or 2 x 4, long enough to reach across the pond,
- a few friends who would love to spend their weekend digging a hole in your yard,
- and enough pizza and beer to keep them motivated.
Building a pond is not quite as easy as it looks. It requires careful planning and awareness of safety regulations and local bylaws, as well as the locations of underground services. Once that has all been taken care of you can assemble your tools and get started. We will tell you all you need to know, and more, about installing flexible pond liners and pre-formed ponds. If you are planning a concrete pond than this section will be of little help to you. This is not something that the average person should attempt by her or himself, and we suggest to get in touch with a contractor specializing in concrete pond construction.
After you have determined the location, size and shape of your pond mark the proposed water area using a rope outline. Take a few steps back, or better yet, have another look from inside your house, preferably from upstairs. Now is the time to make some changes, assuming of course that you are using a flexible pond liner that you have not yet ordered or already purchased. Once you are satisfied with your choice you can continue.
If you are installing your pond over an existing lawn and you might want to re-use the grass somewhere else on your property, carefully remove it to a depth of approx. 4 to 6 inches (10 to 15 cm). Use your spade to get underneath and try to cut it into equally sized pieces.
Begin to dig the hole as per your plan. You can save the excavated soil for future landscaping. Good topsoil can always be used somewhere, and the rest will come in handy in case you decide to add a small waterfall to your pond later.
If you are using a pre-formed pond, excavate the hole to the exact contours, depth and dimensions of the insert you have purchased, allowing for a layer of sand to be put between the soil and the insert to act as a cushion. The sand layer will also allow minor adjustments and levelling of the insert.
Once you are satisfied with your excavation, remove all roots, stones and all other sharp objects from the soil. Roots that can not be removed should be cut back as far as possible. Consult a tree specialist before digging near trees or disturbing their root system.
Then, put down a 2 to 4 inch (5 to 10 cm) layer of sand, making sure to achieve uniform coverage. Drop the pre-formed pond into the excavated and properly prepared hole, lay your 2 x 4 across and check the level all the way around. Then fill the pond with water.
If you are using a flexible pond liner to waterproof your pond, put in the first ledge as planned, making sure that it is level and wide enough to hold things like plant baskets and edging stones or boulders. It goes without saying that the edge of the pond must also be level around the entire circumference. To check, put a long board across the excavation in several spots and use your level.
Continue down to the required depth, constructing as many ledges as desired. Instead of digging straight down we recommend to taper the sides down. This will provide more stability and help prevent the sides from caving in.
Once you are satisfied with your excavation, remove all roots, stones and all other sharp objects from the soil. Roots that can not be removed should be cut back as far as possible. Consult a tree specialist before digging near trees or disturbing their root system.
Then, put down a 2 to 4 inch (5 to 10 cm) layer of sand, making sure to achieve uniform coverage. In lieu of sand, you can also use a non-rotting polyester felt. The cushion layer should also be applied to the sloped sides. Polyester felt will work better than sand in those areas. Do not use cardboard or newspaper as a cushion. They will both rot and eventually disappear.
As there will be quite a bit of foot traffic on the liner during installation we recommend to wear soft bottom shoes or running shoes during the actual liner installation.
Warning: Pond liners are extremely slippery when wet. Pick a nice, warm and sunny day for installing your liner. As the liner might be a bit stiff in cold temperatures it will be harder to unfold and will not conform to the substrate as easily.
Carry the folded or rolled-up pond liner into the excavation and unfold or unroll it.
Smaller liners can also be unfolded outside of the pond. Do not leave it unfolded outside of the pond for too long, though. The sun will heat up the liner quickly, and your beautiful lawn will be burned in no time.
Carefully carry the liner, with one of your friends or friendly neighbors holding it on each corner, into the pond. Do not pull the liner into the pond. First of all, it is heavy, and secondly, you might damage it by scraping it over the soil or getting caught on a sharp rock.
Once the liner is in place allow it, and yourself, to relax. Depending on your chosen shape the pond liner will show wrinkles in some areas. These wrinkles are caused by the fact that the liner is not pre-formed to your excavation but is merely a flat sheet. These wrinkles have no effect on the performance of the pond liner and will later be pressed onto the substrate and sides by the water pressure. You can also eliminate some of the wrinkles by pulling some of them together into one and making a fold in the liner instead.
Make sure that you have sufficient overlap (minimum 12 inches or 30 cm on all sides) around the perimeter of the pond to allow for anchoring of the liner. Now comes the fun part. You can finally begin to fill the pond with water. It is best to put the garden hose into the deepest spot and fill the pond slowly.
As the pond fills with water you can still manipulate the liner to some degree and smooth out any remaining wrinkles.
Once the pond has been filled to the top we recommend to wait two or three days for the water pressure to fully compress the sand and soil underneath and press the liner into all crevices and corners of your excavation. Only after this period of time can you be relatively sure that the liner is in its final position and will not move or pull on the sides. In the meantime, put some bricks or other semi-heavy objects on the liner overlap. This will prevent it from being blown into the water and draining your pond part way.
After the liner has settled into its final position you can start burying the excess overlap. To prevent run-off from entering the pond and possibly washing lawn fertilizer into the water, make a small mound of soil all the way around the pond, drape the liner over it and then bury the rest.
If you are planning to use edging materials that are rough or have sharp edges or corners use a cushion layer between the pond liner and your edging materials. A non-rotting polyester felt is suitable for most applications. If you are worried about puncturing your pond liner you can always use two or three layers of felt. The same goes for heavy edging materials, such as boulders, for example. In this case we recommend using a heavy-duty rubber mat in lieu of felt.
To prevent capillary action and inadvertently draining the pond, terminate the felt or other cushioning materials below the water line or, if extended past the water line, make sure that the pond liner is high enough all the way around to keep the water within the pond.
Make sure you use an appropriate cushion/protection layer if you use concrete blocks or other sharp-edged or heavy materials to raise planter pots.
Pond liner repair kits are available in case your pond liner does get damaged or punctured during installation or afterwards.
Please allow your pond to stabilize for two to three weeks before adding plants and fish. You can, however, add a recirculating fountain pump, underwater lighting, etc. at any time.
A well-balanced water garden requires relatively little maintenance. Occasional cleaning and frequent checks on its equipment and water level are about all that is needed. Unless there is a lot of accumulated debris that can not be removed by other means there is no need to drain the pond on a regular basis and disturb the ecological balance within it. Instead, use a net or pond skimmer to remove falling leaves and other plant debris, i.e. dead waterlily blossoms and leaves, free-floating algae, etc. Dead plant material that has accumulated at the bottom of the pond must be removed. Not only does a clean pond look better but it is also healthier for it and its occupants. Decomposing plant material can smell and it pollutes the water for all the other aquatic life.
If you do drain the pond, refill it immediately after cleaning but allow the water to warm up before adding your plants. Cold water may shock some tender plants. Allow the pond to re-establish for two to three weeks before adding fish.
A major clean-up requiring draining of the pond is the only time when it becomes adviseable to add a large quantity of fresh water to your pond. At all other times we recommend to add small amounts of fresh water only. Keep an eye on the water level and top up the pond when needed, being careful not to alter the water temperature by more than a few degrees. Some people prefer to collect rain water in barrels. The rain water can then be added to the pond as required. This is especially useful if you are on municipal water that is chemically treated.
Algae control is usually the largest maintenance problem in a pond. When setting up a new pond it is normal to have excess algae growth until an ecological balance has been achieved. This balance is achieved through the right proportion of floating, marginal and submerged plants, fish, and scavengers (snails and tadpoles). All plants provide oxygen and consume nutrients in the water. Submerged (also called oxygenating) plants are beneficial because they produce especially large quantities of oxygen and provide supplemental food for fish as well as a place to spawn. Floating plants are most beneficial for providing shade (important for keeping the water cooler – cool water holds more oxygen and is healthier for your fish), preventing water evaporation, and providing hiding places for the fish. Marginal or bog plants provide hiding places for small fish or scavengers and shade in the early morning or late afternoon. Fish excrement, once broken down, provides nutrients for the plants. Oxygen is converted to carbon dioxide by the fish. They also consume insect pests and a little algae, too. Scavengers consume algae, decaying plant material and fish waste, thereby providing nutrients for the plants. It is a complete cycle with each element depending upon the others to provide what they need to survive.
A little algae is natural, will always occur and is necessary for a healthy pond but too much can be detrimental. The amount of algae in your pond depends on the weather, the amount of sunlight, the temperature of the water, the amount of oxygen in the water and the number of nutrients and different kinds of plants present. It can be at its worst in the spring. This is because the algae does not have any competition yet. The situation will most likely clear up once all the plants have started growing again. Be patient. If it doesn’t clear up on its own, something is out of balance. The easiest solution is to add more plants. Both algae and water plants compete for the same sunlight and nutrients in your pond. Adding plants can make the nutrients unavailable to the algae, and increasing the amount of surface area covered by waterlilies and floating plants can decrease the amount of sunlight available for the algae. This is of particular importance if your pond is small and shallow. Having only a few plants in an open expanse of water combined with sunlight will result in warmer water and increased algae production.
If you have a lot of plants and still have too much algae then perhaps there is an excess of nutrients in the water. This could be caused by a number of different factors or a combination of them. One of them could be a run-off problem. Check to make sure that garden or lawn fertilizers are not washing into the pond when it rains. Perhaps you are over-fertilizing your waterlilies or doing it incorrectly. Maybe you have too many fish, and their excrement is causing a nutrient increase. Maybe you are overfeeding your fish. A pond filter/UVC may help to lessen the impact of single-cell-free-floating algae. This is the type that gives your pond the appearance of pea soup. You can also use chemicals to control this type of algae. It is a short term solution and will not eliminate the reason the algae is growing in the first place.
The amount of oxygen in the water is also important. Algae, as a plant, needs carbon dioxide to survive. The higher the oxygen levels, the lower the carbon dioxide levels will be. Oxygen is needed in the water to support aquatic life like fish, tadpoles, as well as aquatic snails, all of which eat algae.
If your fish are coming to the surface gasping for air you have a problem in your pond, namely an oxygen shortage. You can increase the pond’s oxygen levels by adding an aerating nozzle on a pump, planting more oxygenating plants or adding a bit of fresh water.
When water is exposed to air it will pick up essential oxygen. Other than for aesthetic reasons this is why many people use a recirculating pump to run a waterfall or fountain head. Moving water is aerated water.
Blanketweed or filamentous algae is another common problem in ponds. It has been suggested that blanketweed is the sign of a healthy pond as it removes excess ammonia from the water. A pond with blanketweed almost always has clear water. Little consolation to the person whose pond has it. The most common solution is to simply pick it out. There are chemicals available, like Interpet’s Pond Balance, that do not harm your pond and help eliminate blanketweed (you will still have to pick the old stuff out). Another way to reduce blanketweed is to install a magnet. No one is entirely sure why this works. For best results, the pH of the pond should be between 7.0 and 7.5.
Overwintering your pond is a little trickier. It largely depends on the weather conditions in your area and the pond’s depth. The pond can be drained and covered, and all life within it can overwinter elsewhere or the pond can be altered so as to overwinter the way it is. If your pond is deep enough, move frost-sensitive plants below the frost line. Remove fish or take precautions for their survival. Stop feeding them when the water temperature drops below 50 F. The fish are less active now and do not require food. This food will only pollute the water. Remove as much plant debris as you can. In moderate climates consider using an aerating nozzle or bubbler to keep the water moving so that the surface does not freeze over completely. Depending on where you live, you may have to use an electric pond heater in addition to an aerating nozzle. This is important because you have to have an open area to allow for gas exchange to take place, and the fish still require oxygen to breathe.
If your pond is frozen over for more than a few days your fish may suffocate. It is important that you have an open area that allows toxic gases from within the pond to escape and for oxygen to get into the water in the pond. In moderate climates, where ice is rare, you can use a pot full of hot water set on the ice surface to melt it open again. If you need your pot back before Spring, attach a rope or string to the handle so you can retrieve it when it melts through the ice and falls into the pond. Do not pound the frozen pond surface with a hammer as this could kill the fish. In colder climates, you will need to have a floating pond de-icer operating continually.
Unless you can use them year-round, don’t forget to bring your pumps, pond filters and fountain equipment in for the winter. Consult the manufacturer’s operating instructions for proper winter storage procedures for your pumps and filters. In our opinion, the best method for storing your pump over the winter months is to remove it from the pond, clean it thoroughly and run clean water through it for several minutes. Then, keep it in a bucket of distilled or purified water above freezing temperatures. A heated garage or basement would work well. Once every few weeks, turn on the pump and let it run for a minute. Remember to drain any water lines that my crack when filled with ice.
The unpredictable nature of Winter in Canada and the Northern United States makes overwintering your pond more of a challenge. We recommend that valuable and sentimental life be brought indoors if there is any doubt about safe and successful overwintering in the pond.
