Aquascape Designs High-Volume Waterfall Pumps feature flow rates from 1650 to 10700 GPH. They are perfect for streams, waterfalls, and larger water features. The Aquascape Designs 1500, 3000, 4500, 7500 and 10000 pump models are the best choice for Aquascape Designs Mechanical Skimmers. They are specifically designed for use in a water garden skimmer and fit below the filter mats in the Aquascape Designs skimmers. All pumps must be submersed. Designed for continuously use under pond conditions.