AquaPill® 90125APL 2.75" 4 oz WinterPill® Pool Winterizing Formula makes winterizing your pool faster and easier than ever! WinterPill® clarifies the pool water and helps reduce scaling and staining. It is enzyme enhanced and controls non-living organics to control waterline ring and enhance filter performance. WinterPill® patented pre-measured release delivery system helps maintain clear water during the off season, can be used with all sanitizers, is compatible with all pool surfaces and will not affect pool chemistry.