Make your swimming pool water-efficient

A backyard swimming pool can lose 10,000 to 15,000 gallons of water a year from evaporation – that’s about 5 feet of water in an average pool. The evaporation rate varies depending on the pool temperature,
air temperature, humidity and wind speed at the pool surface. The higher the pool temperature and wind speed and the lower the humidity, the greater the evaporation rate.

A pool cover is an effective water and energy conservation device and can save up to 95 percent of the water lost to evaporation. A cover also can reduce heat loss, lower chemical consumption by 35 to 60 percent and save cleaning time by blocking dirt and debris from the water.

All you really need for a pool cover is a large sheet of plastic. While plastic is an effective vapor barrier, a large sheet brought home from the hardware store is probably not your best choice. It will be very difficult to handle and store, it tears easily, and sunlight will deteriorate it rapidly. Covers designed specifically for swimming pools are made from a variety of special materials. According to the U.S. Department of Energy, one of the lowest cost covers made specifically for swimming pools is the bubble, or solar, cover. Bubble covers are similar to bubble packing material but are made of a thicker grade of plastic that includes UV inhibitors.

Vinyl covers are made of a heavier material and have a longer life expectancy than bubble covers. Insulated vinyl covers also are available with a thin layer of flexible insulation sandwiched between two layers of vinyl.

An outdoor pool absorbs 75 to 85 percent of the solar energy that strikes its surface, an important contribution to the pool’s heating needs. A cover will decrease the solar gain contribution: a transparent bubble cover may reduce pool solar energy absorption by 5 to 15 percent, while a completely opaque cover will reduce it by 20 to 40 percent.

Other ways to save water in your pool: Encourage swimmers to limit splashing, and plug the overflow line when the pool is in use. When cleaning around the pool, use a broom and not the hose. Run water features, which increase evaporation, only when people are enjoying the pool.

Backwash pool filters only when necessary. If a timer controls the backwash cycle, check and adjust the frequency of the cycle to ensure optimal efficiency. Where feasible, use backwash water for irrigating lawns, plants or shrubs.
 
Most of all, swim and enjoy your pool. The biggest waste of water is a rarely used pool.