The Kasco Marine Robust-Aire Aquatic Aeration System uses superior diffuser materials and design. This thoughtfully designed, superbly efficient diffuser allows air to escape at a very low pressure, producing much smaller bubbles with less friction loss. The bubbles are approximately 3mm diameter. The U-shaped design of the four diffusers enhances the upward flow of water. Robust-Aire has been tested alongside 6 other leading designs from 4 different manufacturers. Between 10% - 44% more water flow was induced with the same amount of air injected into the water column. The Robust-Aire system simply creates more pond aerating water flow with the same amount of air and energy, making it the most efficient bottom aeration system on the market.