Pleatco Disposable 40,000 Gallon Swimming Pool and Spa Pre-Filter - PPS6120 Pre-Filters fill-water when filling or topping off pools and spas up to 40,000 gallons Removes solids, hard mineral deposits and stain causing trace metals Perfect for use after liner changes, repainting or during spring start-ups Reduces the need for stain and scale chemicals, additional expenses, and chemical dosing Attaches to standard garden hoses and is deal for pools and spas using well water