Get Rid of White Mold in a Hot Tub Easily with These Tips!

Michael Keenan


Hot Tub Troubleshooting

Today, I want to cover how to get rid of white mold in a hot tub. I’ll explain the causes of white mold growth in hot tubs and then I’ll give you step-by-step instructions on how to safely remove it from your spa.

Next up I’ll also give you tips for preventing future growth so that you can keep your hot tub looking its best for years to come. With these simple strategies, you can make sure that your hot tub stays free from white water mold and is ready for relaxation anytime!

Don’t worry too much, white mold is an extremely common problem and one that can be solved relatively easily (be thankful it isn’t a clogged filter or a hot tub rash!).

Here’s all you need to know about solving your white mold problems!

Get Rid of White Mold in a Hot Tub

Quick Answer:

White mold (white water mold in hot tub) is actually a fungus caused by poor hygiene and water management in a hot tub. The best way to get rid of white mold in your hot tub or spa is to drain and chemically clean it. Refill and use 3 times the normal rate of shock treatment. Allow to work. Then drain again and add your sanitizer as normal. Test water before use.

What is White Water Mold – and What Causes It?

The better you know what something is and why it occurs, the easier it gets to solve the problem. Though some people will swear by this, white mold is not, in any form or measure, algae related; it is neither a type of algae nor is it caused by algae.

What, then, is it? Well, white water mold is a naturally occurring form of fungus, making it more of an animal-related issue than a vegetable-related one. Since white mold occurs naturally, it’s an issue that all hot tub owners need to keep an eye out for.

This mold most commonly occurs as a result of improper cleaning and irregular water checks; with these, it can really claim your tub, lock, stock, and twenty barrels!

Once the mold sets in and starts flourishing in your tub, getting rid of it can be a little Herculean, but the great news is that with the right effort, you can bid your mold woes adieu.

How to Identify White Mold

White water mold in hot tub is easy to identify. It appears as a white, fuzzy growth on the surface of the spa shell or interior such as on the steps or around inlets. It often has a slimy texture and can be found in the corners, tucked in the edges, and other hard-to-clean areas. In some bad cases, it can also smell pretty bad – yuk!

Not to be confused with white flakes – caused by calcium scale.

what white mold looks like

How to Get Rid of White Mold Completely

The important thing with white mold? As soon as you see it, get to fixing it! The longer you defer addressing the problem at hand, the more permanent the problem becomes, in your tub.

Here are the steps to get rid of white mold in your tub:

  • Drain your tub completely.
  • Using a hot-tub cleaner (the ‘Oh Yuk Healthy Hot Tub Cleaner’ is a great bet), cleanse all the walls and surfaces of the tub. Really go to town on areas where the mold is visible and scrub away!
  • Give the hot tub filter a chemical cleanse; just a plain rinse will not do the trick. If your filter is over a year old, it may be prudent to throw it out and put a new one in its place.
  • Use a hose filter to refill the tub with fresh water.
  • Shock the hot tub. It helps to use at least a triple or quadruple dose of whatever chemical you’re using for the shock.
  • Once you’ve shocked the water and let the magic work, drain the hot tub out completely, again and refill it.
  • Shock the water again, but this time, use a normal amount.
  • After the last shock, test the water. Ensuring that alkalinity, pH levels, and chlorine levels are all balanced helps keep the water sanitized and cloudless for longer.

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You can test the water by using liquid testing kits, or test strips like the ones that AquaChek sells, which give you the levels of total chlorine, bromine, hardness, pH, alkalinity, free chlorine, and cyanuric acid in seconds. You could also take a water sample and have your local pool facility or hardware store test it for you.

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Yep, getting rid of white mold is a little backbreaking, but before you complain, remember no pain, no gain! And nope, the job doesn’t end here, so don’t sit back on your laurels – regularly testing the water and monitoring it for signs of the fungus is important.

If you see any more, even the slightest bit (fungus can multiply notoriously quickly and easily, so don’t ever write off even the tiniest bit), repeat the whole process listed above.

Safety Precautions Before Cleaning White Mold

I know you are in a hurry to sort that spa out but. Before you start, always remember some basic safety precautions. Wear protective gloves, eyewear, and a face mask while handling any pool and hot tub chemicals.

It’s always a good idea to turn off the power source before starting any cleaning process. Lastly, make sure that all of your cleaning solutions are safe for use on hot tubs and read the instructions carefully and use them as directed. Please don’t mix different products together as this could cause chemical reactions that may be harmful. Stay safe.

How to Prevent White Water Mold Growth

It isn’t without reason that whoever said it, said that prevention is better than cure. Getting rid of white mold can be a pain in the well, everywhere and if you read the above bit, you’re probably emphatically nodding your head in agreement to this.

Therefore, if you don’t want to treat mold, prevent it. Here’s how:

  • Give your hot tub’s walls a thorough brushing at least once a week. Use a scrub brush for the best results.
  • Regularly check the water quality and add any chemicals necessary to oxidize the contaminants in the water.
  • If it’s doable, give your hot tub some sun. Sunlight is the best cure for a range of issues and white mold is one of them! The UV rays act as a natural oxidizer and will help quash the mold.
  • Chemically cleanse your filter every month. Consider replacing extremely old filters.
  • Clean anything that goes into your tub frequently – Mr. Rubber Duck, the water floats, the whole arsenal.
  • If you’ve treated yourself to an hour-long session of rinse, cleanse, shampoo, repeat, shock the tub to keep the water clean (the SpaGuard Enhanced Dichlor Shock comes highly recommended). In fact, regular spa shocking helps maintain the optimum quality of water.
  • Regularly test the pH, calcium hardness, and alkalinity in the tub.
  • Drain your hot tub and clean its walls and surfaces regularly.

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clean and healthy spa

Common Questions:

What causes white mold in hot tubs?

White mold forms in hot tubs when bacteria, dead skin, hair, and body oils all mix to form a fungal growth known as biofilm.

Is white mold in hot tub dangerous?

White water mold in a hot tub is not harmful to humans. It is unsightly and can cause problems with plumbing blockages.

What does white water mold look like?

White water mold is a whitish-colored, mucous-like substance that is usually seen in the corners of the hot tub. It can then turn into large flakes sometimes looking like soggy tissue paper floating in the water.

Can I have white algae in hot tub?

Sometimes people think white mold is a form of white algae – it is not. White mold is a naturally occurring fungus that grows in hot tub plumbing systems.

The Final Word

Though it may seem like a bit of work, incorporating hot-tub-maintaining tasks into your daily schedule will make things easier and prevent any white mold worries, since the mold has never won a battle against a clean, well-maintained tub.

White mold is common, but no one wants to deal with it. This is why it’s better to take the steps to prevent this than deal with it when it does show up. Simple things like how often you change your spa water can make a difference.

Letting things be and not taking the steps to maintain your tub will not just lead to issues with white mold, but to a range of other equally annoying contaminants that take as much work (if not more!) to get rid of.

If your tub does fall prey to white mold, worry not. Though it takes a fair bit of work, you can get rid of it and with the right maintenance and cleaning, you won’t have to worry about mold again.

So, the moral of the story – regularly clean and maintain your hot tub to prevent problems like white mold!

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!