How to Remove Foam or Bubbles From an Inground Pool

It’s a warm summer day, and you’re looking forward to diving into the cool, refreshing water in your swimming pool. But your dream is squelched when you discover your in-ground pool has morphed into a bubble bath. After eliminating the possibility of someone having dumped soapsuds into the pool, the chemistry of pool maintenance kicks in as you attempt to discover how to remove foam and bubbles from your pool and the reason for your frothy nightmare.

Shower Before Swimming

Most public pools have an outdoor shower and signs posted that request you to shower before entering the pool. It’s not because the pool management thinks you’re dirty, but instead, they want you to shower because it washes off the oils and lotions you’ve slathered on your body and into your hair. Those oils create a film that floats on the surface of the water. The same practice holds for private swimming pools, and it's one of the causes of film, foam and bubbles.

An ineffective pool filtration system also can be the cause of the bubble bath. Trying to save on electricity by cutting back on the operation of the pool filter is costly in the long run. The filter needs to run for at least 12 hours every day to properly cleanse the water and prevent the bubbles from forming.

Better Living Through Chemistry

Good pool maintenance is all about chemistry. There’s a reason your pool service person approaches your in-ground pool with a cart full of chemicals and test-tubes. If you're into maintaining the pool yourself, you know the importance of each of those little vials to test the water’s balance. Even if you use a pool service, it’s always a good idea to have a water-testing kit available, along with a selection of the chemicals necessary to combat an immediate problem.

Testing: 1 - 2 - 3

After you’ve skimmed the pool with a hand-held skimmer and dumped the film and bubbles into a separate container, it’s time to test the water to discover the water deficiency causing the foam. Use a test strip to determine the water’s pH, its level of acidity. It should read between 7.2–7.6. If it reads higher than 7.6, the water will turn cloudy, your skin will become irritated, and it indicates that the chlorine isn’t doing its job.

Anti-Foam Chemicals at Work  

Correct a high pH level by using sodium bisulfate or muriatic acid. Just be careful when using either as they are acids. Read the instructions to determine the quantity and location for adding the acid to the water. Test again in 24 hours.

Low pH levels are corrected by adding soda ash to the water. If you need to raise the pH level by .2, use 6 ounces of soda ash per 10,000 gallons of water. Once the pH levels are corrected, the water should clear, and the foam and bubbles should disappear.

A pH lower than 7.6 reveals acidic water that causes severe damage as it tries to self-correct and create a balance. Attacking the pool plaster or siding compound and going after the metal in the filter, pump and heater are two targets of overly-acidic water. Swimmers also suffer from low pH with eye and nose irritations.

Test strips are also effective when measuring the alkalinity of the pool water, another cause of pool foam. The alkalinity strip should read between 100–150 parts per million (ppm) to avoid foam.

Chlorine is also used to clarify water in a pool, and it's where you start when performing routine maintenance. Chlorine kills bacteria and prevents the growth of algae, the green stuff that turns your crystal blue water into a sea of green goo. Also, adding a few ounces of a high-quality, non-foaming algaecide once a week while combating the foam should bring your water back to normal.