How To Remove And Prevent White Flakes In A Hot Tub


So there you are, physically and mentally exhausted from a long day at work and excited to take a well-deserved soak in your hot tub. But then you notice those tiny white flakes in water, turning what should have been a nice and relaxing break into a hot tub cleaning nightmare. Truth be told, this is a pretty common problem among many hot tub owners so don’t worry because you’re not alone. Fortunately, there are ways to get rid of these pesky white flakes in the hot tub, but before we get to that, let’s first try to identify what you’re dealing with.

Calcium Scale and White Mold

Those white flakes floating in your hot tub can either be any of these two: loose calcium deposits or biofilm. It is crucial to know the differences between these two since each of them will require a different cleaning approach.

Calcium Deposits or calcium scale is the more common cause of this particular problem. As you may have already guessed, this happens when there is too much calcium in the water as is the case with hard water. Calcium usually builds up on the hot tub’s shell and lines, and when the hot tub is turned on and the water starts circulating, tiny flecks of calcium break loose and are distributed throughout the water.

White Mold can also be the culprit behind this attack on your hot tub. These organisms thrive in warm and moist environments just like your hot tub and its surrounding areas.

So how do you know which of these two are you dealing with? Here’s a simple test.

  1. Collect eight ounces of hot tub water (together with the white flakes) in a cup.
  2. Add 20 drops of bleach or chlorine to the water in the cup and stir.
  3. Set aside 30 minutes.
  4. If after 30 minutes the white flakes are still in the water, then they’re most likely to be calcium scales. If not, then they’re probably white mold.

Once you’ve identified what you’re dealing with, you can now move on to getting rid of them.

Removing Calcium Scale Deposits

Removing calcium scales in your hot tub is relatively easy depending on the severity of the calcium buildup. For newly developed calcium buildup, applying a cleaning solution to the affected areas and scrubbing the calcium deposits off should be enough. However, if the calcium buildup has been around for quite some time, then you’ll need to roll your sleeves because there’s significant work to be done.

  1. Drain the hot tub and wipe out any remaining water on the shell and let it air dry.
  2. Generously spray the affected areas with a calcium remover and let it sit for at least five minutes (or depending on the manufacturer’s recommendations). If you don’t want to use a commercial calcium remover, you can use a homemade cleaning solution made up of equal parts of white vinegar and water.
  3. After letting the solution sit, scrub away the calcium deposits using a soft-bristled nylon brush.
  4. Once you’ve gotten all the calcium deposits out, rinse the tub with clean water before refilling it.

To help reduce the chances that you’ll have to deal with this problem again in the future, here are some tips:

  • Regularly check and balance your hot tub water. Calcium scales generally form when pH levels in the water are too high.
  • Use a calcium scale preventer from time to time. These products break down significant amounts of existing calcium deposits so that it takes them longer to accumulate.
  • If you live in an area with hard water, consider using water softeners. These help to remove or reduce the number of minerals in the water that goes into your hot tub.
  • Use a quality hot tub filter remember to clean the filter regularly as well and replace it as recommended.

Removing White Mold and Biofilm


Compared to calcium scale deposits, white mold and biofilm is a tougher and more serious issue. To effectively deal with this problem, you’ll need to get rid of the biofilm to deprive the organisms that produce a white mold of food and nourishment. To get rid of biofilm, you’ll have to subject your hot tub to a deep clean.

1. Remove and Clean the Filter

Before cleaning your hot tub, first, remove and clean the filter. If the filter isn’t that dirty, you can simply use running water and a soft-bristled nylon brush to clean it. Otherwise, you’ll have to soak the filter in a mixture of water and cleaning solution, preferably overnight to loosen up the debris and grime buildup before cleaning. Also, check that the filter is still in good working condition. If not, consider replacing it with a new one.

2. Purge the Plumbing Lines

Biofilm develops inside your hot tub’s pipelines, so you’re going to have to purge your plumbing to really get rid of them. This step is crucial because no matter how clean your hot tub’s exterior is, the water passing through the biofilm-laden plumbing will only bring the bacteria back into your hot tub. To purge your plumbing lines, simply add a biofilm remover into your hot tub and let it circulate for a few hours. If it’s been a while since you last drained and cleaned your hot tub, you may want to consider letting it circulate overnight.

You might also like: How To Get Rid Of Yellow Algae In A Hot Tub

3. Drain the Hot Tub

After letting the biofilm remover circulate, you should now drain the biofilm-filled water out of the hot tub. Most hot tubs can be drained through a drain spigot located underneath the hot tub. If not, check your owner’s manual for specific instructions on how to drain your hot tub.

4. Clean and Rinse the Hot Tub

With all the dirty water out, you can now start cleaning the hot tub. Use a hot tub cleaner and a sponge or a soft cloth to wipe the surface of the hot tub clean. Do the same for your hot tub cover to remove any white mold that may be sticking to it. Afterward, rinse the hot tub and the cover with clean water, wiping along with a clean rag to make sure that you remove any remaining residue from the cleaning solution. Be sure to get all the residue out; otherwise, the water will start foaming once you power on the hot tub.

To prevent biofilm buildup in the future, you’ll want to keep the following tips in mind.

  • Stick to a regular hot tub cleaning schedule. Remember, biofilm forms as a result of improper hot tub cleaning and maintenance practices.
  • Shock your hot tub water This will help to kill off any bacteria that was able to survive the deep clean.
  • Always keep an eye on your water chemistry. Balanced hot tub water is less likely to hold any bacteria or white mold.

Globo Surf Overview

Hot tubs are pretty much the same as any other appliance or fixture in your home. If you neglect to clean and maintain it, it will start showing some problems such as those pesky white flakes in the water we’ve been talking about. That said, regularly cleaning and sanitizing your hot tub is the best way to prevent any of these white flakes in the hot tub. Whether they’re calcium deposits or white mold, consistently maintaining your hot tub should help ensure that you don’t run into any of them.

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