The Aquapill #73 Solar Pill 2 3/4", treats up to 12K gallons of water and prevents pool water evaporation and heat loss by using a simple measureless capsule, getting the benefits of a solar blanket without the cost or hassle involved. The Solar Pill is not affected by automatic pool cleaners, is safe to use with all pool types and completely biodegradable. For complete protection against pool water evaporation and heat loss, simply drop into your pool skimmer and its time-release formula provides all-day protection. Made in the USA.