Why Is My Hot Tub Water Cloudy And Foamy?

Why is my hot tub water cloudy and foamy? How much foam is normal in a hot tub? Bubbles in a tub are usually a sign of a relaxing bath. But in a hot tub, …

Why Is My Hot Tub Water Cloudy And Foamy

Why is my hot tub water cloudy and foamy? How much foam is normal in a hot tub? Bubbles in a tub are usually a sign of a relaxing bath. But in a hot tub, they could mean something entirely different.

Foamy hot tubs can happen from time to time and, luckily, are easy to manage when it does happen. While the foam is not considered harmful, it’s also not something that you want in your hot tub.

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There are several reasons why hot tub foam appears, and it usually has to do with a lack of sanitation and filtration. But before you panic, rest assured that it’s a simple problem to deal with.

Why is My Hot Tub Water Cloudy and Foamy?

Aside from misappropriated bubble bath, hot tub foam can be caused by a variety of other things. In order for foam to appear in your tub, it needs water, air, and surfactants, otherwise known as the sticky molecules responsible for reducing the surface tension of liquids.

The reduction in surface tension allows water and oil to mix much more easily. This in turn forms a “skin” on the surface of the water.

When air is added to your hot tub via the jets, it forms a bubble. The more surfactants are in the water, the more bubbles you’ll see. Over time, the bubbles will continue to build up, thus causing the foam that you’ve come to know and hate.

It’s vital to keep your hot tub clean and its chemistry maintained but in order to do so, you need to use a variety of chemicals and calcium.

This is so that the surfactants we mentioned earlier are neutralized. If you don’t keep up with your hot tub, these surfactants tend to build up from a variety of sources.

Cosmetics, hair care products, sunscreen, laundry detergent, and even lotion are just some of the many things that you can find in your hot tub water.

When people wearing any of these products bathe in your hot tub, the products get washed off in the hot tub, thus creating the foam. Another hot tub foam culprit is food and drinks.

This is quite normal; after all, there’s nothing wrong with enjoying a cocktail and some snacks while you relax in your hot tub. If you accidentally spill into your tub, however, you could end up messing with the chemical balance of the hot tub.

Body oils and dead skin cells are yet another cause for hot tub foam. As gross as it may seem, every time that you bathe in a hot tub, the water gets polluted with your oils and skin cells.

You can usually tell if the culprit is body oils because you may be able to feel an oily ring on the shell of the hot tub as well as on the surface of the water.

This is just one of the many reasons why it’s so important to sanitize your hot tub on a regular basis. Biofilm is also something that can cause foam build up in a hot tub.

Biofilm is bacteria and microorganisms that stick to a surface in the hot tub. Most often, this happens to be your hot tub’s plumbing.

Eventually, the biofilm will grow a layer of slime over it that can be hard for sanitizers to treat. Even something as tough as chlorine would have a hard time with biofilm.

The longer you leave biofilm to sit in your hot tub, the more it will require sanitizer, thus leaving less and less to break down surfactants as well as other substances that will inevitably cause the water to foam.

Lastly, the hot tub foam could be caused by low calcium levels that can also decrease the surface tension in the water. Low calcium levels, otherwise known as soft water, can also cause a lot of damage to the hot tub itself as well as the spa equipment.

If you think that this might be the problem, simply test the water with test strips to make sure that your calcium levels are where they should be.

Unbalanced water in general can result in your water turning green and even cause it to give off a bad smell. To prevent this, make sure that you turn off your water softener so that you are not filling your hot tub up with soft water.

How Much Foam Is Normal in a Hot Tub?

Nearly every hot tub will always have a little bit of foam in it, even those that are well kept. However, this could become an issue when the foam gets higher than an inch.

Not only is the foam annoying, but it’s also a way for bacteria to travel, thus emulsifying it to the surface where it can be easily absorbed by bathers.

Of course, you may have simply just fallen victim to a prank and someone may have doused your tub with bubble bath soap.

Even if this is the case, you’ll still have to drain the water and clean the tub to make sure that you’ve gotten rid of any soap residue.

If not, you could be dealing with hot tub foam for years to come. Because of this, it’s important to keep the bubble bath soap in your bathtub and away from your hot tub.


Natural Way To Get Rid of Foam in Hot Tub

Perhaps the easiest way to get rid of the foam in your hot tub is to use anti-foam agents that you can spray over the surface of the water.

The chemical then begins to spread over the hot tub water, thus destabilizing the soap and foam. The only thing that you should keep in mind when using an anti-foam agent is that this only provides a temporary fix.

If you want to deal with the problem head on, you’ll have to drain the water from the hot tub. The first step in getting rid of hot tub foam for good is to test your water.

This is so that you can find out the water’s pH, alkalinity, and sanitizer levels. This also allows you to check for any lingering surfactants.

After gathering up all of the information you need, you’ll need to drain all of the water in your hot tub. You will probably also have to do a line flush and replace your filters.

To drain the water, use a line flush product and then remove the filters in the hot tub. If the filters haven’t been changed in a while, be sure to replace them.

Otherwise, you can simply clean them and replace them. Be sure to unplug your hot tub and disconnect anything else that may be plugged into it.

Your hot tub may have a drain plug at the bottom of it, or you can drain it using a sump pump. After all the water has been drained, you should also consider cleaning your hot tub both inside and out.

Start by wiping down the inside of the tub with a solution of vinegar and water. After wiping it down, be sure to rinse it out.

If you’ve used a hot tub cleaner instead of the vinegar and water solution, be sure that you’ve gotten rid of it entirely before refilling your hot tub. If not, you will be left dealing with the same problem you started with.

When you are sure that your hot tub is clean and free of any chemicals, you can go ahead and refill it again with a hose filter attached to your garden hose. This is so that you can keep any chemical impurities from getting into your water.

When your hot tub has been filled again, check the water for pH, alkalinity, and sanitizer levels once again. You should also shock your hot tub once a week, being sure to leave the cover open after doing so.

How to Prevent Hot Tub Foam

Now that you have gone through the trouble of getting rid of the hot tub foam and cleaning your hot tub, you’ll want to do everything in your power to prevent hot tub foam from becoming a nuisance again.

Make sure that the water is always balanced and that you’re maintaining a constant sanitizer residual. More importantly, make sure that you shower or rinse before entering the hot tub to get rid of any soap, makeup, or other product you may already be wearing.

If there’s laundry detergent left behind in your bathing suit, a quick rinse will wash it away. If you have recently shampooed your hair, try and avoid going underwater so as not to get your shampoo in the water.

Make sure that you’re also using chemicals you can trust to clean your hot tub. Many cheap chemicals have fillers in them that can contribute to the very hot tub foam that you’re trying to keep away.

Lastly, be sure to keep away any food or beverages from the water. If you want to snack while in the hot tub, be sure to do so away from the water. Otherwise, you could end up spilling in the water.

As mentioned earlier, use a chlorine-free Spa Shock without odor to oxidize the water in your hot tub. Spa Shock is also a great way to help break down body oil, makeup, lotion, shampoos, or any other products that may have been left behind in the water by bathers.

The amount of Spa Shock that you should use on your hot tub simply depends on how long and how often you use your hot tub, how many people are in it, and whether or not any products have been left behind.

Make sure that you’re also opening up the hot tub cover on a regular basis so that you’re letting the water breathe and get enough oxygen. Speaking of water, be sure to drain and change out the water in your hot tub every four to six months for best results.

When looking to purchase a hot tub, be sure to purchase one that has a good filtration system. This is one of the most important factors to look for in a hot tub and what will help keep hot tub foam at bay.


While it might look fun from the surface, hot tub foam is certainly not something to be played with. It is a sign that there is a significant amount of bacteria building up in the hot tub water; therefore, you need to find a solution as soon as possible.

As mentioned previously, there is only so much that chemicals can do to treat the water and at some point or another, you’ll have to completely drain it altogether.

Be sure that when you do drain the water, you’re taking the opportunity to get your hands dirty and giving your hot tub the thorough and much-needed scrub down that it needs.

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