Why Your Hot Tub Is Foamy And How To Clean It

When a hot tub isn’t maintained correctly, owners might start to notice some things in the water. Often this comes in the form of mineral build-up on the jets or algae on the walls, but one sign that your hot tub maintenance hasn’t been frequent enough is foam in the water.

When we use hot tubs, we’re shedding lotion, shampoo, laundry detergent, and everything else we come into contact with—so, if not cleaned enough, the foam in the water may build up over time. Fortunately, it’s easy to fix this by cleaning the hot tub, including paying attention to the filters.

Let’s take a closer look at foam in a hot tub and what you can do to eliminate it (and prevent it from happening again in the future).

Why is Your Hot Tub Foamy?

Man having massage in hot tub spa

If your hot tub is foamy, the most likely reason is build-up over time. When people use the hot tub, they still have some residue from shampoo, conditioner, body wash, and laundry detergent.

None of these things are meant to be used in a hot tub, but they’re unavoidable with general use, so you must clean the hot tub frequently. If you don’t, the foam can build up over time and eventually become noticeable. 

Foam in the hot tub can also be due to the pH balance being thrown off. The pH of a hot tub should be between 7.2-7.8; if not kept at this level, the chemical balance in the water won’t be right. This is another reason you might see foam, mainly if you haven’t used the hot tub heavily or cleaned it regularly.

Is Foam in a Hot Tub Bad?

Foam in a hot tub, although rarely detrimental, is never good. You shouldn’t see foam in your hot tub water; if you do, you must clean the tub or use a pH test strip (on Amazon) to check the levels and fix them.

How to Treat Foam in a Hot Tub 

Chlorine-free spa shock (on Amazon) can help clean the water. However, ensure you don’t use a typical pool shock, as this is likely far too much for a small hot tub. You can also use a defoamer, but it won’t fix the root cause, and the foam will return.

How to Treat Foam in a Hot Tub Naturally 

A 10:1 ratio of vinegar and baking soda poured into your hot tub can help eliminate the foam. You should use around one gallon for every one hundred of gallons in your water. If this doesn’t work, however, it may be that you need to clean your hot tub properly.

How to Clean the Hot Tub

If you need to clean the hot tub because the foam doesn’t go away with quick fixes, you’ll have to drain the water—but first:

  1. Put some jetline cleaner into the water and run the pumps for fifteen minutes, clearing out residue in the jetlines.
  1. Once you’ve done that, attach a hose and drain the water into your yard or, preferably, the sewer line. There are laws against doing it in the street.
  1. Then gently wipe down the walls of the hot tub with vinegar and water (equal parts) and an old rag. Make sure you wipe around the edge of the jets and clean the filter, too, as there can be a build-up on this.
  1. After you’ve done this, you can refill the water.

You should drain and clean your hot tub every three months or more if it gets particularly heavy use and seems to need it.

How to Clean a Hot Tub Filter 

Cleaning the filter can be the most crucial part of cleaning a hot tub, so it’s imperative to know how to do it right.

  1. When your hot tub has been drained, remove the filter cartridge and spray it down with some water. Use a gentle setting on your hose, as a pressure washer could damage the filter.
  1. If necessary, you can then use an old toothbrush to—again, gently—scrub between the pleats and get residue or debris out.
  1. Once you’ve done this, soak the cartridge in equal parts vinegar and water for at least one hour.
  1. After an hour or so, remove it from the solution.
  1. Rinse it thoroughly before putting it back in the hot tub and filling it up again.

Steps to Prevent Foamy Hot Tub Water 

Beautiful woman relaxing in hot tub

Foamy water can be a nuisance, but if you’re on top of the maintenance, you can take steps to avoid having to deal with it.

Avoid Putting Swimwear in the Laundry

If you can avoid putting swimwear in the laundry, this is ideal for preventing detergent residue from getting in the water. Instead, rinse it in cold water and don’t use any detergent or fabric conditioner.

Rinse off Before Getting in

It’s a good idea not to shower immediately before getting in the hot tub, but if you have to, you should rinse off thoroughly.

Make sure any lotion and body wash is gone from your skin, and rinse your hair thoroughly to get rid of shampoo and conditioner. Keep scrubbing with your hands and if product is still coming off, keep rinsing.

Take off Make-up

Make-up is another product that can cause foam in the hot tub if it gets in there. As hot tubs get very warm, sweat can cause make-up to run down your face and enter the water. Therefore, taking the make-up off is a good idea (and rinse your face, so no remover is left on there).

Test the Chemical Balance Frequently

It’s critical to frequently test the water’s chemical balance to ensure the chlorine levels and pH are correct. Hot tubs that sit in the sun will take more damage because the sun will burn up the chlorine, so you may need to test them more.

Use a Hot Tub Cover

Using a cover, you can protect your hot tub from the sun and other products that may get in there. Make sure it fits well and is made of a good material, usually vinyl.

You should also take care to clean the cover. Rinsing it down with plain water every few days is fine, as this prevents debris from getting trapped under it and into the water—often causing foam.

Scoop Out Debris

As well as using a cover to prevent debris as much as possible, you should scoop out any that still manages to get into the water. Keep a pool net handy, so you can use it every day or two to scoop out any twigs, leaves, or bugs that have fallen into the water.

Keep a Cleaning Schedule

Although you should only have to drain the hot tub every three months or so, this may be more with frequent use—and it certainly can’t go any longer.

Make sure you keep your cleaning schedule up to date, or you may have more significant problems than foam to deal with, like hard mineral build-ups and malfunctioning equipment.

Do Not Use Products Not Meant for a Hot Tub

Lastly, you should ensure you aren’t using products in there that aren’t meant for a hot tub, such as:

  • Body wash
  • Bath bombs
  • Bubble bath
  • Shampoo and conditioner
  • Aromatherapy products (not made for a spa)

All these things can not only contribute to foam in the tub, but they will also throw off the balance of the water and can even cause damage to the equipment.

To Finish

Ultimately, you shouldn’t have to worry about a little bit of foam in the water. It’s usually easy to use spa shock to get rid of it or drain the hot tub and clean it if that time has come around.

Still, with how sensitive hot tubs can be, it’s best to keep up with the maintenance and test the chemical balance frequently, as it means less work overall.

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