Pool Foam – What Causes It and How to Get Rid of It

how to get rid of pool foam

Although kids or teenagers may find a foamy pool to be very fun to play in, unfortunately it is not a good thing.

The most common reasons for pools to start foaming are due to a chemical imbalance as well as the presence of algaecides, soaps, personal care products, or household cleaners.

To get rid of foam in your pool, you may need to rebalance the chemicals, do a full backwash cycle, let the foam dissipate over time, or add some chlorine or anti-foam chemicals to speed up the process.

If you want to know how to get rid of your pool foam, you must first learn what are the possible causes so you can take appropriate action afterwards.

Why does your pool foam?

There are many reasons why your pool can have foam on the surface. Pool bubbles typically consist of three things: water, air, and surfactants.

Though none of these components are an issue individually, when they combine together, they create foam that can obscure vision and be indicative of a chemical imbalance.

Surfactants (soaps, oils, etc.) are the most likely culprit because they are sticky by nature, they lower the surface tension of water, and this makes it easier for oil-like substances to mix with air and water.

Let’s look at the most common causes of pool foam.

Algaecides

Judging by how many people are asking the question “how to get rid of algaecide foam in pool”, algaecide is a very common culprit of foamy pool water.

This is likely because you have added too much algaecide for the amount of water your pool holds. You should carefully read the instructions on the packaging and add smaller amounts at a time so you don’t accidentally add too much.

The best course of action is not to add more chemicals, but rather to simply wait it out as the foam is not likely to last for long.

In the meantime, you can use a net to scoop out the foam on the surface, and turn off any fountains or waterfalls because they can cause more foam to form.

Soaps

Another very common cause of pool foam are soaps such as those found in hair care products, or those used to clean pool toys.

Soap is obviously very foamy and when enough enters the pool, it will create layers of foam along the surface.

Detergents used to wash swimwear may also get into the pool and contribute to the increase in surfactants.

Personal care products

Chlorine is notorious for drying out hair and skin, and it is highly recommended that you apply moisturizing products to protect your skin and hair.

However, products that people use to keep their skin supple and safe from sunburn, such as lotions, creams, ointments, and sunscreen can cause foaming if sufficient amounts enter the pool water.

That said, this is rarely the issue in backyard pools compared to public pools since not that many people are sharing the pool.

Rather than wearing so many products into the pool, consider saturating your hair and skin with freshwater by showering beforehand.

Human byproducts

We humans are actually quite dirty, and even the most hygienic people will be surprised at how much dead skin cells, fatty acids, and sweat they produce.

Well when you’re swimming, your body doesn’t stop producing these byproducts and they will end up in the pool. As mentioned, oil is a contributing factor in foamy pools.

There’s nothing we can do about our body’s natural process. To limit how much byproducts enter the pool, you should shower beforehand; the rest is up to the chlorine to handle.

Household cleaners

When you are using cleaning products to clean your house near your pool or to clean the pool itself, some of it will end up in the pool water and cause foaming.

The cleaning chemicals may either cause the pool foam itself, or it can interact with the chemicals already in the pool and cause foaming.

When using household cleaners near your pool, you may have the urge to hose it off when you’re done, but this can cause the chemicals to enter your pool.

Instead, try wiping the cleaner away with a damp cloth to limit how much unwanted chemicals make it into your pool.

Chemical imbalance

If you added the pool chemicals in the proper amounts, they should prevent foaming from occurring. That said, ironically they can cause foaming themselves if you add the improper amounts.

That is why it is so important to test your pool water often to ensure the water chemistry is balanced.

It is also better to err on the side of caution and add less than you think you need just in case your calculations are off. At least then, you can always add more if you need to, but you cannot take out chemicals you’ve already added.

How to get rid of pool foam

So now that you are aware of the most common causes of pool foam, you have a much better understanding of how you can clear it. Below are the optimal methods you can do.

Balance the water chemistry

When you are adding chemicals to your pool, you will need a pool test kit to determine valuable information such as the pH level, free chlorine, alkalinity, and so on.

From there, you can add chlorine, soda ash, or any other chemicals you may need to bring the chlorine, pH, and total alkalinity readings to the “safe” range. Then give the chemicals a day or two to work their magic and you will have a clean and clear pool again.

Use anti-foam products

You can specifically use anti-foam chemicals to reduce the amount of foam in your pool. Read the instructions carefully to know how much to add and if there are any negative reactions that can occur.

Be aware that adding yet another chemical can start to make your pool into a chemical soup. However, if you have a pool party coming up and don’t have time to wait for the foam to dissipate on its own, then you may not have a choice.

Anti-foam chemicals are a band-aid solution that do not address the problem, but can make your pool temporarily foam-free so you can have your pool party.

Backwashing

Removing and backwashing the pool filter can help to remove the foam stuck in the filter.

Furthermore, draining a few inches of pool waiting and adding in fresh water can dilute the chemicals in the pool, including whichever one is causing the pool foam, and will reduce the amount of foam in the pool.

Just waiting it out

Most of the time, pool foam will take care of itself. Just switch off the pump system, add a bit of chlorine, and just wait a day or two for the foam to clear.

The chlorine should kill off anything causing the foam and eventually the foam currently in the pool will dissipate on its own, leaving a clear pool behind.

Can you swim in a foamy pool?

Assuming that the water chemistry is balanced, it should be safe to swim in a foamy pool. Make sure to confirm that the water is safe by using a pool test kit and checking that the readings are normal.

That said, the pool foam does give off unsanitary icky vibes so perhaps you should just wait it out after all.

Photo Credit: Miguel Discart (CC BY-SA 2.0)