It’s inevitable. At some point during hot tub ownership, your water will become old, dirty, or unbalanced. This leads to undesirable reactions in the water that cause it to look cloudy, foamy, or discolored. The first key to solving any problem is to understand what it is. With that in mind, we will go through the potential causes of these issues, outline some of the visual and textural properties of cloudy, milky, and foamy hot tub water to help you achieve an accurate diagnosis, teach you how to fix those problems if you have them, and how to prevent them. 

What is Foamy Hot Tub Water?

Foamy hot tub water describes a foamy type of film that can develop on the surface of the hot tub water. Unlike cloudy and milky water, it is much easier to pinpoint the cause of this issue.

What Causes Foamy Water?

Foamy water is caused by excess buildup of nonorganic matter in your hot tub. Simply put, products like lotions, soaps, sunscreen, makeup, and body sprays dissolve into the hot tub and build up over time. When they do, they create a foamy film that sits on top of the water that can leave residue on the shell around the water line

How Do You Fix Foamy Water

1. Treat the Cause, Not the Symptoms

We know the cause of foamy water is nonorganic matter buildup. This is largely preventable. By developing a clean usage routine, such as showering, removing makeup, or spraying yourself down, you can eliminate most pollutants before they ever reach the hot tub. It is important to not only develop this routine for yourself, but to make sure any guests adhere to it as well. Especially if they are frequent guests.

2. Shock the Water

Apply shock to the water. This will oxidize the foam and allow it to flow through your filter. Be sure to clean your filter thoroughly after this process as there will likely be some inevitable buildup.

3. Use a Defoaming Product

If that doesn’t work, you could try adding a defoaming product like SpaBoss Defoamer. This will work quickly but should be viewed as a short-term option since it doesn’t actually prevent the foam from coming back.

4. Drain, Clean, and Refill your Hot Tub

If all else fails it may be time to cut your losses and drain the hot tub. Before doing so however, we recommend using a spa purge product like Water’s Choice™ Clean & Drain. When used as directed, this product will help get gunk out of your spa’s plumbing, ensuring you start over with fresh, clean water. Once the hot tub is drained, you can take this opportunity to thoroughly clean it and check components, ensuring everything is running smoothly.


Proper maintenance, water care, and regular use of your hot tub will fix and prevent the majority of issues hot tub owners face. While that sounds so simple, we understand how difficult it can be at times, especially for new owners. If you are testing your hot tub water more than once a week, struggling to keep your water balanced, or have any other questions, please stop by for a free water test and personalized advice.