Does Chlorine Affect the Evaporation of Pool Water?

Evaporation

• Evaporation is the natural and uncontrollable process of converting liquid into vapor form. Evaporation creates most of the rain and snow in the earth's atmosphere. The clouds hold this evaporated water vapor and it turns into precipitation. Lower humidity, high winds and hot temperatures increase the rate of evaporation. The lower humidity leads to evaporation because the air is unsaturated and has room to hold the vapor. The same principal applies to high winds, which continuously provide the liquid surface of water with clean unsaturated air.

Chlorine

• Chlorine is one of a few controllable factors a pool owner has to slow the rate of evaporation. Chlorine is necessary to sanitize your pool water and keep it free of germs and other forms of bacteria such as algae. Chlorine however breaks down and loses its efficiency from things such as wind and high temperatures. When the chlorine decreases, it leads to a higher rate of evaporation. A properly sanitized pool will slow evaporation, but not prevent it completely.

Solar Covers

• Solar covers are a good way to reduce evaporation and conserve the chlorine levels in your pool. A solar cover applied to the pool surface will slow down the evaporation rate of chlorine. A solar cover is plastic UV-stabilized material that creates a vapor barrier between the water and the cover resulting in a reduction in evaporation. The water vapor has nowhere to escape. It also helps to heat your swimming pool water as well.

Chlorine Stabilizer

• Chlorine dissipates quickly during humid and hot weather. It requires you to constantly add chlorine not only to reduce the evaporation but to also keep it sanitized. If the pool chlorine is not added as needed, the water becomes a breeding ground for cloudiness and eventual algae blooms. Chlorine stabilizer is a chemical you can add in conjunction with your regular water chemistry that helps the chlorine last longer in the water. Some chlorine products are manufactured with stabilizer inside the product. These are usually sold as chlorine tablets.