How to Get Foam Out of Your Hot Tub—And Keep It Gone

Splish, splash I was taking a bath... Wait a minute.

If you’ve got foam in your hot tub, I can tell you one thing right here and right now: that is not soap. In fact, it’s a substance that isn’t even remotely clean. When foam occurs in a spa, it’s a sure bet that nasty bacteria has been permitted to thrive freely in the water.

So no, it’s not a good thing that your hot tub has foam. It’s cause for alarm. But as with all health emergencies, the best course of action is to take it seriously, and solve it immediately. I’ll explain why your hot tub has foam, what that foam really is, and how to get it out of the spa—for good. 

Why Do Hot Tubs Have Foam? 

Alright, we’re not cool with the bubbles. But why are they cropping up in the first place? 

Get your safety goggles on—just kidding, you don’t need them while you’re reading this article. But it’s important to be safe when handling chemicals. That’ll come later.  

This is about to get scientific.

The foam in your hot tub is caused by a certain type of molecule called a surfactant. You might also hear surfactants referred to as total dissolved solids (TDS).  

Basically, one end of a surfactant molecule is attracted to water and one end is attracted to air. That’s why foam exists on your hot tub’s surface. Mix a surfactant with water, air, and those powerful jets, and you’ve got yourself a bunch of foam.

This isn’t to say that foam should be in your tub. When your hot tub is frequently shocked and has the perfect chemical balance, the bad guys that make up surfactants are zapped away.  

Now you know why your hot tub has foam, and you know there are bad guys involved. I’m guessing you want to know exactly who they are.

So What Exactly Is in That Foam, Anyway? 

Surfactants have a way of hiding in plain sight. In other words, the substances that cause hot tub foam don’t actually seem sinister—and they’re all around us, even useful in other circumstances. Some are even impossible to avoid. 

This is all the more reason to stay on top of that chemical balance. You hear me?

Pro-tip: Keep your hot tub covered when you’re not using it. But what if your cover isn’t quite holding up in the storm? Try the Sunnora 350 GPH Automatic Cover Pump to keep it dry and secure. According to customer Richard Hogan, “works great.”  

Sometimes the Problem... Is You 

Now this one’s really impossible to cut out. It’s you. As in, your body.  

It’s not something we love to talk about, but it’s the truth: our bodies secrete, uh, stuff at a constant rate. Body oils and dead skin cells can and will exhaust your sanitizer, especially if you’re skipping your weekly hot tub shock. 

If your sanitizer is exhausted, you’ve just sent a hand-signed invitation to surfactants to come on in. “The water’s fine!” 

Personal Care, Don’t Care 

You take care of yourself. I see you. And hey, I’m not suggesting you go full-on hippie anytime soon. Unless, of course, that’s your thing. Peace and love.

Most of us use some combination of shampoo, conditioner, makeup, lotion, deodorant, and soap. Although you might consider that shampoo washed out and that lotion soaked in, the traces of these products come with us into the hot tub. From there, they wreak havoc.

That is, if havoc is a lot of foam and a wonky chemical balance. It’s especially important to shock your hot tub after a big gathering. It’s simple math: multiply the amount of people by the amount of products you think they applied that day, and that probably equals to: surfactants. 

Your Swimsuit’s Sudsy! 

So you washed your suit. That’s great! But yeah, that detergent isn’t great for chemical balance. I’m not saying don’t wash your trunks. I’m just saying that you shouldn’t skip any maintenance days—especially if you don’t want those surfactants floating around. 

How to Choose the Right Chemical for You 

In this section, I’ll be explaining how to choose the right de-foaming chemical. Just kidding—there is none. Yes, there are plenty of chemicals on the market advertising that they can get the foam out of your hot tub fast. And, they can—usually within a day. 

But we’re not here to put a band-aid on the problem. We’re here to get that foam out of there for good. 

Using a de-foaming chemical is a temporary solution. Your foam will be here today, gone tomorrow, and back the next day. It’s just not going to get the job done. 

Do you have a variable-speed pool pump yet—and the lower monthly energy bills to show for it? The Blue Torrent 2 HP Variable-Speed Pump is the one to try—it’s ultra-powerful, allows for more thorough circulation, is eligible for rebates, and pays itself off in under a year in energy saved. As customer Dave Schmidt says, “My pool has never looked cleaner. I am pleased with my new pump!” 

How to Get Foam Out of Your Hot Tub—in Three Steps 

Ready to get this nasty stuff gone? I don’t blame you.  

Don’t worry, this is not a job that requires a call to your local maintenance guy. It won’t take more than three simple, straightforward steps. No invoices necessary. 

1. Put Your Water to the Test 

It’s best to know exactly what you’re working with, right at the outset. Using water test strips, check the pH, alkalinity, calcium hardness, and sanitizer levels of your hot tub—oh, and total dissolved solids (TDS), because it’ll probably help to know just how many surfactants are floating around.  

If you’ve got foam, some of these chemicals are seriously off. Knowing which ones need a little more attention in the future will prevent similar messes.

2. Hit the Reset Button

It’s just like starting over... 

Though in this case, it actually is starting over. You want to drain your entire tub for this step, give it a deep clean, and then fill ‘er back up again. (By the way, you should be doing this every three months or so!)

In order to drain your tub, simply remove the filters, turn off the power to your hot tub, disconnect all electrical cords, and trip the breaker. Then, drain the water out using a submersible pump or the drain plug.

Next, clean out your tub with the patented BLACK+DECKER 360-Degree Bristles Pool Brush. This brush was designed by longtime pool maintenance experts to get every tough to reach, tight corner—without hurting your back in the process. You can use a solution of one part vinegar to four parts water, or a hot tub cleaner. Make sure to rinse your tub thoroughly—or you’re just asking for foam 2.0. Don’t forget to clean (or even replace!) your hot tub filters.

3. Back to Balance

Time to finish the job. Refill your hot tub with a good ol’ fashioned garden hose—preferably with a hose filter to keep other damaging chemicals out of that fresh water.

Test the water again, add the chemicals, and circulate your tub for a day. That’s it!

Don’t Let It Happen Again!

Unless you’re soaking frequently and want to reduce maintenance, I’m not going to tell you to shower or rinse your swimsuit before getting into your hot tub. I’m not even going to tell you to make sure your hair never touches the water. 

The whole point of having a hot tub is to enjoy it. 

But I will say that you need to make sure you’re brushing down the walls of your hot tub, testing your water, and shocking your water every single week.

Interested in maintaining an ultra-clean hot tub—without hurting yourself in the process? Try the patented 360-Degree Bristles Black & Decker Pool Brush, developed by long-term pool professionals to eliminate the hip and back pain associated with one-sided brushes.  

Foam-tastic, You’re Done!  

Whew, that was a close call. Foam can indicate some serious health risks. But now that it’s good and gone, you’re back to safely soaking. That means that the next time you feel like you’re taking a bath, you actually will be. And for now, nothing calls for an ahhhh like a freshly-cleaned spa. Enjoy.


For additional information on how to get rid of mustard algae, check out this article. Having problems getting rid of white water mold in your pool? Read more here.

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