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What Causes Air Bubbles in Swimming Pools?

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Owning a swimming pool is a pleasurable experience when everything's going okay. However, a myriad of issues can arise in regards to a swimming pool. For example, a swimming pool's water is supposed to be crystal clear at all times. Unfortunately, swimming pool water can be obscured by many things, including an excess of air bubbles. By themselves, air bubbles in a swimming pool aren't harmful. Air bubbles in a swimming pool, though, probably are an indicator of pool filter problems.

Air Bubbles

Air bubbles in a swimming pool usually appear because air has gotten into the filtration system somehow. The most common pathway that air bubbles in a swimming take to get into the pool itself is from the pool's water returns or "jets." Swimming pool water returns are how water that has been sent through the filtration system is returned to the pool. Often, air leaks will develop in swimming pool filter pumps, resulting in air bubble-laden filtered water being sent to a pool.

Leak Locations

Swimming pool filters should be closed systems, and the filter mechanisms shouldn't be open to the air. A swimming pool is very efficient at pulling in water, filtering it and then pushing it back out. However, air is easier for a swimming pool filter to pull in and then push out than water. Common air leak locations on swimming pool filters include fittings around the suction side of the filter pump as well as around the pump's lid.

Eliminating Bubbles

Air bubbles in swimming pools due to air leaks in swimming pool filtration systems are a mechanical repair issue. Eliminate air bubbles caused by air leaks in pool filter pumps and water return lines by checking all fittings and filter pump lid seals. In addition, if you have air bubbles in your swimming pool, you need to check the pool's filter pump housing drain plugs. To keep air bubbles out of a swimming pool, replace pool filtration system gaskets and seals as needed.


Sometimes swimming pool owners confuse air bubbles in pool water with froth or foam. Froth or foam in a swimming pool is most often due to low calcium hardness levels in the pool's water. Low calcium hardness in a swimming pool means its water is too soft. If your swimming pool is suffering from low calcium hardness, you'll need to harden the water by adding calcium chloride according to instruction. Swimming pool calcium hardness should be between 200 and 400 parts per million.

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