The Classic Tropical Fish is an automatic LiquidHeat dispenser using a pump controlled by a miniature computer. The fish starts working as soon as it is placed into your pool. Our LiquidHeat is dispersed into the pool, floats to the surface and creates an eco-friendly, invisible cover for your swimming pool. The Liquid Solar Blanket will reduce water evaporation by up to 50% and evaporation accounts for up to 90% of heat loss from a pool. The Classic can last up to 30 days in a small to medium (0 - 400 sq.ft) total pool surface area. Below are instructions, directions and FAQ related to the Tropical Fish. Just drop it in the pool and let it do the work!. Tropical Fish is made for 12Ft. round and larger. If your pool is less than 400sq.ft. surface area (21 round or 14 x 28 rectangular pool) one Tropical Fish is all you need for a month's pool use. Your Tropical Fish will last for approximately 30 days. For larger pools use two(2) fish at the same time. If required you can keep your Tropical Fish away from automatic pool cleaners by tying it out of the way to a ladder or railing. The Tropical Fish works best by adjusting your swimming pool jets down. Keeps pools hotter, Longer!. Last up to 30 days. Easy to use. Reduces evaporation. No cutting or squeezing.