The Flowclear™ 1500 gal. Sand Filter from Bestway® is a highly efficient and environmentally friendly way to keep clean water flowing through your above ground pool. It is a more cost effective solution as the pump uses silica sand instead of a traditional filter cartridge. While those cartridges need to be replaced every 2 weeks, silica sand lasts up to 3 years. The sand will trap dirt and debris, but a pre-filter strainer basket catches larger things so that the pump will last longer. The filter also comes with the ChemConnect™ Dispenser, which maintains clean, healthy water by providing a stable level of chlorine that is evenly dispersed throughout the pool. This product comes pre-assembled, and is compatible with most 300 - 11,200 gallon above ground pools, as it comes with an adapter for pool valves with an outer diameter of 1.5 in. The sand is not included with this filter - required sand size is #20 silica sand, 0.45-0.85 mm, approximately 20 lbs. The filter also works wonderfully with Bestway’s Polysphere™ Filtration Balls.