What Causes a White Foamy Subtance on the Top of Pools?

Chemistry Imbalance

• Swimming pool water is made up of several different kinds of chemicals and substances that keep the water clean. If one or more of these chemicals becomes unbalanced, then the top of the water can begin to appear white and foamy. To check for such problems, use a chemical check strip kit that can be purchased from any pool supply store. If any of the chemicals are off, raise or lower the levels as needed. It is recommended that you check your water's levels at least once per week.

Algae

• It is possible that the white, foamy substance is a form of mold or algae. Algae is typically green or even pink, but when it dies due to the use of algaecides, it turns white. To clean the water, the white substance needs to be removed as much as possible, using a pool skimmer, and thrown out in a trash bag. The walls of the pool need to be scrubbed clean as well. Check the pool's pH levels. If they aren't within the proper range between 7.2 and 7.6, the correct chemicals need to be added. Chlorine and algaecide should also be added to kill any remaining algae in the water.

Lotion and Sunscreen

• During the hottest part of the summer, many swimmers coat themselves in lotions and sunscreens to protect their skin from the sun. However, if the lotion and sunscreen isn't water-resistant, it often washes off in the water and collects at the top of the water, causing it to look white and foamy. The only solution for this is to make sure swimmers are using waterproof products and only using the recommended amounts. While there are water defoaming products on the market, they are mainly used in spas and not so much in pools.

Other Causes

• It is possible that air is getting into the water return line of your pool, and this, along with a chemical imbalance can cause the water to appear foamy. If the filter for the pool becomes clogged from algae, hair or debris, it can cause the water to look foamy and cloudy. To correct these problems, you'll need to check the lines and filters for any problems. If necessary, you can contact a pool company to come and inspect the lines for you.