SeaKlear AquaPill AP71 WinterPill Swimming Pool Winterizer Pill Floats under your winter cover all season Performs well with mesh safety covers Patented 6-month delivery system Safe for all surfaces and filters One small WinterPill treats up to 30,000 gal All-in-one formula is an exclusive 4-part blend to make spring openings faster and easier Floats under your winter cover all season Performs well with mesh safety covers Patented 6-month delivery system Safe for all surfaces and filters