Hayward StarClear Cartridge Filter 25 Square Foot Cartridge. 1.5" Female Fitting. Hayward C250. The Hayward Star-Clear cartridge filters will provide crystal clear pool or spa water. This 25 sqft filter has a single locking knob that securely fastens the head to filter tank, eliminating bolts or clamps and makes it very easy to remove the cartridge and clean. The tank is made of a durable injection-molded body for corrosion-free performance. Residential Design Flow Rae: 25 GPM Effective Filtration Area: 25 ft.2 Pipe Size: 1 1/2" FIP Dimension, Width: 10 1/2" Dimension, Height: 19 1/2"