Natural Chemistry Pool Magic Spring & Fall Clear, Perfect Water with HALF the work! We are not exaggerating when we say your spring opening will be hassle-free and take less time. For years, homeowners and commercial service companies have reported dramatic results -- especially with mesh covers. This powerful formula prevents winter waterline ring, preserves pool liners and finishes, and reduces staining and the need for acid washing. Why do you need to use Pool Magic in the spring and fall? The reasons are simple really... The fall or closing application of Pool Magic will provide a residual level of enzymes in your water over the off-season, which prevents water line rings etc, from forming. When you fill your pool in the spring this dilutes the concentration, so the additional spring or opening dose is necessary for fresh fill water. Try it once, and we guarantee you will never go another season without it! Close your pool with Pool Magic and next spring you will enjoy Clear Perfect Water with half the time and work! One Liter will treat up to 25,000 gallons.