Pond and Waterfall Filters To keep your pond or water feature looking beautiful, it is important to provide proper filtration. There are two forms of filtration critical to maintaining a healthy ecosystem pond: mechanical and biological. Through mechanical and biological filtration, ecosystem ponds will process fish waste, uneaten fish food, leaves, and runoff from lawns. In ecosystem ponds, mechanical filtration is provided by a pond skimmer and biological filtration is provided by a BioFalls® Filter. To keep your pond or water feature looking beautiful, it is important to provide proper filtration. Features and benefits of Aquascape Pond and Waterfall Filters are noted in the following pages, making it simple and easy to select the correct filter for your application. Pond and Waterfall Filters.