Heat trapper forms a thin layer of protection on the surface of your pool. When used bi-weekly, this product will prevent excessive water evaporation, minimize heat loss & reduce the amount of pool chemicals needed to maintain your pool. 1 shake bottle before use. 2 with the filtration system on, pour 4 oz. Per 15, 000 gallon of pool water in front of the jets at the deep end of the pool, or into the Skimmer. Run the filtration system daily. 3 repeat this dosage every 2 weeks, for maximum effect.