Waterco Fulflo 2165500NA TC500 500 SqFt Tri-Cartridge Filter 510 lpm. Fulflo Tri Cartridge Filters are designed to effectively filter out suspended solids from your pool. They contain three individual pleated filter cartridges, maximizing its dirt holding capacity and minimizing filter maintenance. These filters are built to endure the rigors and pressures of outdoor environments, made from specially engineered polymers tested for durability and strength, and are ideal where backwashing may not be practical or areas where water may be scarce.