Being a pool owner comes with a lot of maintenance and hard work. Unfortunately, despite having a good cleaning routine, your pool can run into trouble, like developing pool foam. Though it looks gross, you don’t have to freak out about your pool developing foam. While it’s not a completely natural process, there are easy, quick solutions that allow you to combat and prevent swimming pool foam from further developing in your pool.
In this article, I’ll go over what is pool foam and what causes it before diving into how to treat and prevent it.
Main Takeaways
- Pool foam appears as thick, frothy bubbles in your pool and appears when the water is “thick.”
- Shampoo and toiletry products, high bather load, total dissolved solids, low calcium hardness, low quality or too much algaecide, and other pool chemical issues can all cause pool foam.
- To treat pool foam, use a hand skimmer, balance your chemicals, shock your pool, and add anti-foam chemicals.
- To prevent pool foam, ensure all swimmers take a light shower and the pool is chemically balanced.
What is Pool Foam?
Pool foam is a collection of thick frothy bubbles in your pool. If you’re a beer drinker, you’re probably familiar with a layer of white froth on top of the liquid. This is what pool foam looks like, just replace beer with pool water.
Foaming shows a pool’s health—or the lack thereof. It may be difficult to tell the difference between bubbles and foam, but in general, the foam will be thick and remain on the surface, while bubbles are airy and will pop much easier.
Foam shows up on the surface of a pool when the water is “thick.” A few different factors can cause this “thickness” of the pool water—some human-made, some purely from a chemical imbalance. We’ll go over all the different causes of pool foam and how to combat them.
How is Pool Foam Different from Air Bubbles?
Bubbles occur naturally, or at least they appear underwater and get pushed up to the surface when jets are running. So how can you tell whether you are dealing with foam or bubbles? Foam may appear in patches or even a thick layer when jets aren’t running and will float on the surface.
This is where “thickness” plays a role as well. Bubbles are light and airy with little surface tension. On the other hand, foam is thick, dense, and does not pop as easily as bubbles because foam is made of a buildup of organic materials and not air.
To be clear, bubbles aren’t that great, either. Read my article on why you have air bubbles in your pool for more.
What Causes Pool Foam?
Pool water balance is essential for proper pool maintenance. There are several things that can cause pool foam to form in your pool, including imbalanced chemicals, shampoo or other hygiene products, and too many swimmers in the pool at one time.
Pool foam isn’t inherently dangerous or unsafe. In fact, it can be perfectly safe to swim in a pool with foam as long as your chemicals are correctly balanced. However, I still recommend removing the foam as soon as possible so you have crystal clear, not “thick,” water.
Shampoo and Toiletry Products
If you jump in the pool after a shower, you still likely have a residue of shampoo, conditioner, body wash, etc. These products can mix with your pool water and cause pool foam. Other products like laundry detergent, deodorant, makeup, lotion, moisturizer, body spray, and sunscreen can also cause pool foam if they mix with the pool water. Furthermore, anything the human body can shed or expel can cause foaming issues.
How To Fix It
If you have pool foam from toiletry products, your best bet is to shock your pool. You should ask swimmers to rinse off before they get in the pool and avoid putting on deodorant, dry shampoo, body sprays, or other products before getting in the water. This is why public pools ask people to shower before entering.
High Bather Load
A bather load is the number of people swimming in a pool at one time. The more people that swim in your pool, the more sweat, detergents, urine, and oils will enter your pool water, making it more likely for pool foam to form.
For this reason, many public pools limit the number of people that can be in a pool area. If too many swimmers are in your pool, the sanitizers can quickly become overwhelmed.
How To Fix It
Fixing this issue is pretty much the same as above. Shock your pool, possibly with even a double dose of shock to ensure you get rid of all the contaminants in the water. You may also consider limiting the number of people that can swim in your pool, or at the very least, ensure everyone rinses off or, better yet, showers before swimming.
Total Dissolved Solids (TDS)
Foaming in a pool can also be caused by high levels of total dissolved solids (TDS) in the water. TDS is the measure of solid matter that has liquefied. Foreign solids like oil, soil, and dirt dissolve in pools. High levels of TDS make pool water look cloudy and can even make it taste salty.
Swimming in pools with high TDS levels is unhealthy and makes a pool harder to maintain, leading to a dangerous environment. Pool operators must maintain low TDS levels to have a clear, healthy pool. The ideal TDS level in a pool is between 500-2,000 mg/L.
How To Fix It
Your pump and filter system are the first line of defense against TDS, so you should ensure they are running for at least 8 hours a day and functioning properly. One of the most effective ways to get rid of foaming and maintain low TDS levels is to drain and refill the pool with fresh water.
Low Calcium Hardness
Low calcium hardness levels in your pool water can cause the water to become too soft. This is a culprit for numerous problems, including low pH, corrosion, etching, and pool foam. Luckily, this is a fairly easy issue to fix.
How To Fix It
The best way to fix low calcium hardness in a pool is to increase it, of course! Add a calcium hardness increaser or add calcium chloride to your pool and bring the level up to between 175 and 225 ppm.
Low Quality Or Too Much Algaecide
While chemicals are vital for correct pool maintenance, they can also cause foaming issues, especially if you’ve recently added chemicals to your pool. It depends on the chemical, but algaecide tends to make pool water foamy.
Make sure you follow the suggested doses per bottle instructions, as too much algaecide can also cause foaming, as it can cause your pool water to thicken. Spring pool opening kits may also cause pool foam. When a pool is first opened at the beginning of the season, there is no algae for the algaecide to kill, so the water may become agitated and frothy.
How To Fix It
If you add too much algaecide to your pool and foam forms, don’t panic! Foam caused by algaecide should break down on its own, but you can always skim your pool’s surface if you’d like to speed up the process. Algaecide may cause foaming, but non-foaming algaecides are available. It’s also best to avoid 10% polymer and copper-based algaecide because they can cause foaming or stain your pool due to their metal content.
Other Pool Chemical Issues
Your pool may have foam if the chemicals are imbalanced. It is important to consistently test your pool water using a pool test kit to ensure your chemicals sit at the right levels. If your chemicals are imbalanced, especially your pH or chlorine, pool foam may form.
If your pool water is imbalanced and you have to make adjustments, I recommend measuring the pH, alkalinity, calcium hardness, and total chlorine and then adjusting them separately in that order.
How To Fix It
Staying on top of your pool chemistry is one of the best ways to prevent a plethora of problems with your pool. Test your water, top up your chemicals to the right levels, and maintain these levels to keep your pool as healthy as possible. Here are the recommended pool chemical levels:
- Free Chlorine: 2-3 ppm
- pH: 7.2-7.8
- Alkalinity: 80-120 ppm
- Calcium Hardness: 175-275 ppm
- Salt: 2,700-3,400
- Bromine: 3-5 ppm
- Biguanide: 30-50 ppm
Check out my article that dives into pool chemistry for more on this.
How to Treat Pool Foam
If you’ve run through all the previous causes and instructions and still find your pool has foam in it, there are still a few tricks to try. To combat foam successfully, I recommend following the instructions below.
Step 1
The first thing I recommend for getting rid of pool foam is to use a hand skimmer. It can get rid of most of the foam immediately, and with balanced pool water, the rest should quickly clear up.
I like this algaecide from BioGuard since it's copper-free, which should help prevent your swimming pool from turning a nasty green color.
Step 2
If your pool’s chemicals are balanced, you can try shocking your pool with chlorine and then leaving its pump running until the foam fades.
When you shock a pool, you add chlorine to the water to sanitize it. This process gets rid of contaminants, bacteria, and cloudy water. It also prevents ammonia and living organisms, like algae, from dominating your pool.
In The Swim has a reliable cal hypo shock that is effective and easy to use.
Step 3
The final step I recommend for ridding your pool of foam is adding anti-foam chemicals. Anti-foaming chemicals are designed and concentrated on getting rid of pool foam without interfering with the other chemicals in your pool.
I constantly recommend this anti-foam from BioGuard. Simple to use and effective.
If you’ve tried all these solutions and are still experiencing foam in your pool, you can always call an expert to come out and assess the situation. They might be able to pinpoint a solution for you better and help you eradicate the foam from your pool once and for all.
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Preventing Pool Foam
Prevention is always easier than trying to find a fix after the fact! I recommend all swimmers take a light shower to remove cosmetics such as hair spray, deodorant, soap, body lotion, shampoo, oil, makeup, sunscreen, and laundry detergent before swimming in your pool.
Pool foam looks gross and can seem like a handful to deal with, but as long as you know what to look for, it takes no time at all to get rid of pool foam. Keeping your pool chemically balanced is a surefire way to make sure you never have to deal with that pesky foam ever again.
Frequently Asked Questions
Why is there foam in my pool after shocking?
While shocking your pool is one of the best ways to get rid of pool foam, it is not the only solution. If your pool has foam due to low calcium hardness, algaecide, or a high level of total dissolved solids, you will have to use other methods to get rid of the foam.
Why is my pool foaming after adding algaecide?
Some algaecides contain metals that will cause the foam to form in your pool. Steer clear of 10% polymer and copper-based algaecides, as these tend to cause more foaming in your pool.
Is it safe to swim in a pool with foam?
Pool foam is unsightly and may make you wonder if it is ok to swim in. However, most of the time, swimming in a pool with foam is entirely safe as long as the chemicals are balanced. That said, while the pool foam itself may not be dangerous, it can be a sign that your pool is unclean and needs to be shocked.
Have questions? Shoot me a note; always happy to help.
