Foam in Hot Tub? How to fix the problem

Hot Tub Foam

Foam in Hot Tub water is a common problem. If you are lucky, it is not too difficult to get rid of the foam in your Hot Tub, and you can help prevent its recurrence by understanding why the foam formed in the first place.

In this article we will look at what causes foam in your Hot Tub and how to get rid of it.


What causes Foam in Hot Tub?

If you have a problem with foam in your Hot Tub, there are three possible reasons:

Incorrect Calcium Hardness

If the calcium levels in your Hot Tub water are incorrect, it can cause foam to form. Too little calcium can also be a problem as it can damage the internal parts of the Hot Tub and leave stains and deposits. It is known that soft water is responsible for more bubbles and foaming than hard water, so it is important that the water hardness level is correct to prevent excessive foaming.

Incorrect pH

If the water has the wrong pH and is too acidic or alkaline, it can cause many problems, including excessive foam in the hot tub. It is important that you regularly check and adjust your pH levels to ensure that your disinfectant is working properly and to prevent further problems. Sometimes the foam problem is only reduced by correcting the pH of the water.

Dirty Hot Tub water

To cause a small foam epidemic, the water in your hot tub does not need to look really dirty – it could actually be perfectly clear. After all, your water collects all kinds of deposits, especially on the bodies of bathers, such as shampoos, lotions, moisturizers, etc., and is a source of water “pollution”. These lotions and potions all contain surfactants, so-called molecules, which are the cause of the hot tub foam problem. Surfactants can remain unnoticed in water until air is added to the equation and foam problems occur.


How to Get Rid of Foam in Hot Tub

There are a lot of things you can try to get rid of the foam in your Hot Tub. The first two methods are related to water maintenance and you will find that even if you cannot perform your normal maintenance for a short period of time, you will still experience the accumulation of foam and cloudy water in your Hot Tub. You can still get foam even if you continue to maintain the water, in which case foaming water most likely means that you are ready for a complete water change.

Check Your Alkalinity and PH

The first thing you need to do is get a test strip and measure your total alkalinity and PH. Simply soak the test strip in the Hot Tub water and check the color of the test strip vial using the color chart. The total alkalinity of the water should be between 100 and 120 parts per million. If you need to increase the alkalinity, use an alkalinity enhancer for the Hot Tub. If you need to reduce the alkalinity, use the PH decreaser for a Hot Tub. Allow the Hot Tub to run for 30 to 60 minutes before repeating the test and change the Hot Tub again if necessary.

Add Clarifier or Anti-Foam

You may want to add clarifier and Anti-foam to the water. If you have a problem with turbid water and foam, this may work extremely well. The clarifier removes the foam particles and allows the filter to pick them up again. After inserting the clarifier, run the Hot Tub with the nozzles for about an hour, then remove the filters and clean them thoroughly. As with the use of the deformer mentioned above, adding a clarifier is really only a quick solution if you have a problem with foam and turbid water. Some people add a clarifier to clean water to give it an extra spark, but when you use it to solve a problem, you inevitably have to clean and fill the entire tub. Anti-Foam and Clarifier are not a real solution, they just mask the problem.

Clean the drain and refill the Hot Tub

If all else fails, the only way to get rid of your foaming water is to drain, rinse and refill the Hot Tub completely. Generally, you will need to do this approximately every three months, depending on your Hot Tub usage and the quality of your maintenance program. You can also measure when it is time to change water by calculating the total dissolved solids or TDS in the Hot Tub. If the amount is 1500 parts per million or more, then it is definitely time to change the water.

How to Prevent Foam in Hot Tub in the First Place

You probably know by now that it is very difficult to get rid of the foam in the Hot Tub once you have  it. As with many things, prevention is better than cure, and if you take a few quick steps, you can both reduce the risk of foaming in the Hot Tub and increase the time between complete water changes.

  1. Set up a maintenance schedule for your Hot Tub – One of the most important things you can do to prevent foam from entering your Hot Tub is to follow a daily maintenance schedule. This includes checking the alkalinity and pH of the water daily, monitoring calcium levels, maintaining disinfectant levels, and administering regular shocks to the Hot Tub.
  2. Showering before entering the Hot Tub – It is only advisable from a hygienic point of view to ask bathers to shower before entering the Hot Tub.

Final Thoughts

Nobody likes to have foam in their Hot Tub, and this is one of the things that is usually a symptom of a deeper problem. Remember, any decent accumulation of foam has shown that your water is dirty and potentially full of bacteria. In fact, the trick might be to adjust the water chemistry and give the Hot Tub a good boost of disinfectant or shock treatment. If you do this, you have come a long way to ensure a foam-free comfortable soak!


Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi


Hi, Andi here. I own and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Today, I've helped over 1000 DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi

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