The 1,500 gal./5678 L Bestway Flowclear sand filter is a very effective and environmentally friendly way to keep your above-ground pool water clean. This solution is more economical because the pump uses silica sand rather than a traditional filter cartridge. While the cartridges must be changed every 2 weeks, the silica sand lasts up to 3 years. Sand captures dirt and debris while a strainer basket with pre-filter catches larger items, allowing the pump to last longe