Simply pop out the pre-marked hole on the SolarPill and place in your skimmer! The SolarPill liquid rises to the surface of the pool, forming an invisible layer on the surface. Will not damage the vinyl or any other pool surfaces and is absolutely harmless to skin contact. Once the SolarPill is empty, simply remove from your skimmer. Use 1 SolarPill per 30,000 gallons. Lasts approximately 30 days.