Kasco Robust-Aire Diffused Aeration Systems are more effective at aerating deeper waters than a floating fountain or high-volume surface aerator. Kasco Robust-Aire becomes effective at 8 feet of depth and increases efficiency with respect to water flow as the water deepens. Water is pumped directly from the bottom, all the way to the top. Kasco Robust-Aire compressors can inject air 50 feet deep!