Why does my spa have white flakes / white scale? (And how to solve)

Noticed the black or white flakes in your spa? These flakes can be harmful to your spa’s filtration and plumbing system. Learn the causes and how to eliminate them to keep your spa running smoothly.

This article discusses what causes white or black flakes in your spa, how to remove them, and ways to prevent them from coming back, so you can enjoy crystal clear spa water!

This article mentions brand names not affiliated with Spa Store™ or Vortex Leisure Pty Ltd. You can see the list of brand owners at the bottom of this article.

What is the white stuff in my spa?

Did you notice white or yellow flakes floating around in your spa water or gathering near the drains? These may look similar to dandruff, but they’re usually a result of calcium or magnesium build-up or excessive grease and scum.

By contrast, black flakes can often be attributed to mould. The appearance of pink or green flakes or biofilm is usually due to algae or bacteria.

Why are there white flakes in my spa?

There are several possible reasons why there are white flakes in your spa. In many cases, it could be a combination of different factors such as whether proper sanitation is observed, the type of water used, or whether the filters are cleaned regularly.

Hard water is the most common cause of white flakes. Hard water contains high levels of calcium and magnesium. When not properly treated, calcium can solidify in the spa’s interior, typically around the waterline.

Hard water can also cause your spa water to look cloudy. Click the button below to learn more about hard water and how to fix it.

How do I know what causes white flakes in my spa?

If you notice white flakes in your spa, the first thing you need to do is diagnose what is causing the problem. To do that, here’s a guide to get you started.

Step 1. Check the type of white flakes

White flakes aren’t all alike. Different kinds of white flakes are usually caused by different things, so knowing which one you’re dealing with can help you make a plan for removal and prevention.

Calcium build-up usually looks like chalky, white deposits. They are usually hard and may occur at the waterline of your spa. They often feel like hard chalk and will crumble like one when scraped.

If you notice soft, white floating flakes, they are usually caused by grease and scum build-up in your pipe lining. These floating flakes tend to smear on your fingers when in the water.

Step 2. Determine if you are sanitising enough

Regardless of whether the white flakes in your spa are soft or hard, the main problem usually lies in water sanitation. Improper sanitation is one of the most common culprits of white scale build-up in spas.

If the white flakes are located in just one spot instead of around the water line or saturated in the water, it is usually a sanitiser issue.

To know whether you are sanitising enough, ask yourself the following questions.

  • How big is your spa? The size of your spa determines how much sanitiser you need on a regular basis. You can check your spa manual specifications to learn more about the size of your spa.
  • What sanitiser are you using? There are different types of sanitiser you can use in your spa which require different dosages and dispersal instructions. Make sure you are using appropriate amounts, and if you are combining products ensure that you are using complementary chemicals that will not harm your spa’s water balance.
  • How much sanitiser are you using? Depending on the type of sanitiser you’re using, you may be using too much or too little.
  • Are you following the recommended dosage? Water sanitation isn’t something you can eyeball. Each sanitiser will have a recommended dosage instruction which may depend on the volume of water in your spa. Make sure that you are following the instructions of your preferred sanitiser regarding usage and dosage.
Spa minerals vs Sanitiser

Click the button below to find out more about the best spa sanitisers you can use.

What is the white mould in my spa pool?

White mould in a spa pool is a type of biofilm that forms from bacteria, dead skin cells, and body oils and lotions. White mould in a spa pool often appears as white flakes or tissue paper in the water.

White flakes and white mold in spa pools are related but not the same thing. White mould is a type of contaminant that grows in the spa's plumbing and can be caused by various factors such as improper water chemistry, stagnant water, and lack of regular cleaning and maintenance.

How do I get rid of white mould?

To get rid of white mould in a spa pool, you can follow the steps below.

Use Chlorine

Use granular chlorine to super-chlorinate the water. Maintain a chlorine level of 20 ppm or more for 72 hours to decontaminate the spa and eradicate the white mould.

Clean All Surfaces

Clean all the surfaces of the spa pool, including the plumbing, with a suitable hot tub cleaner to remove the mold

Filter Maintenance

Remove and clean the filters per manufacturer's instructions. Generally, spa filters require replacement within a 12 to 18-month timeframe, so ensure they are replaced as needed.

Water Balancing and Maintenance

Regularly test the water for pH, alkalinity, and calcium levels, and ensure proper water circulation and filtration. It's also recommended to change the spa water completely at least every three or four months.

How do I remove calcium scale in my spa?

Hard scale at the water line doesn’t necessarily harm you, but it is likely to cause problems in your spa’s filtration, pipes and plumbing system if you leave it for too long.

If you notice hard scale in your spa, it’s best to remove it as soon as possible and take proactive steps to prevent them from coming back in the future.

Follow the instructions below to help you get rid of calcium scale in your spa permanently.

Step 1. Scrub off hard scale using mild acid

To remove calcium scale from your spa, you can use diluted white vinegar and a fair bit of elbow grease. Vinegar is a mild acid that will dissolve the scale, but you don’t want to use it at full strength because it may damage your acrylic shell.

To make the task easier, you can use a non-scratch scrubbing pad, microfibre cloth, sponge or soft brush to help you remove the white scale.

Step 2. Treat hard water

Once you have removed the scaling on your spa, it’s time to treat the main problem. If hard water is causing calcium deposits to build up in your spa, using a water softener to minimise the calcium and magnesium levels of your spa is vital.

Use water test strips to read your water hardness and then use a water softener accordingly.

We also recommend using a scale inhibitor like BioGuard Aquality Balancer which works like a mineral net that grabs minerals and binds them together so they can be caught in the filters to avoid calcium deposits from building up.

Step 3. Re-balance water

When you find a white scale located in just one spot of your spa, the sanitiser is the likely culprit. This may be due to the sanitiser not mixing properly into your water which may cause it to eat into your acrylic.

To avoid this, make sure you are putting your sanitiser in properly. Adding sanitiser directly to your spa water can cause discolouration in one particular area on your spa shell. Ensure you are mixing sanitiser with water in a separate container so it fully dissolves before tipping back into your spa.

Following your sanitiser’s label instructions, re-balance your spa and ensure that levels are at recommended points.

What causes soft white flakes in my spa and how do I fix it?

Soft white scale flakes usually come from grease and scum build-up in your pipe lining. If you see flecks of brown floating in the spa, it can also indicate grease and scum build-up.

Step 1. Clean the pipes

To remove soft white flakes, you will need to deep clean your spa pipes. Use a pipe cleaner like the Zodiac Spa Pipe Cleaner to clean your spa pipes and remove oil and other contaminants. You may have to do this a few times until you don’t see the flakes appearing or coming out of the pipes.

Learn how to clean pipes with a pipe degreaser in the detailed article.

Step 2. Empty and refill the spa with water

Once you have cleared out the white flakes, we recommend that you drain your spa to change out the water. While doing this, make sure to check that no scum or grease has built up in the acrylic. Refill your spa and sanitise by following the sanitiser instructions.

How do I stop white flakes from coming back?

You have finally managed to get rid of soft white flakes in your spa, but what if they come back?

To avoid possible white flake build-up in your spa, here are some practices that we recommend.

Ensure that you are balancing water and sanitising properly

Proper maintenance and sanitation are crucial in keeping a spa in excellent condition and avoiding scaling or scum build-up. Make sure to test your water balance frequently, follow usage instructions, and use only the right amount of sanitiser.

For more information about spa water care, read the detailed article on spa water chemical maintenance.

For more information about spa water care, you may use our detailed guide.

Clean filters regularly

Your spa filters are your first line of defence against bacteria and mineral build-up. Make sure to clean or change them out regularly to keep your water safe and avoid white flakes.

Learn how to clean spa filters.

Change your water regularly

Aside from cleaning your filters and ensuring proper sanitation, it’s also important to remember to change your water regularly.

While spa water can be kept clean for months at a time with the right chemicals and proper hygiene, it’s still important to drain and refill the spa once every 3 to 6 months.

Practice good water hygiene

Aside from keeping your spa water sanitised using sanitisers, it’s also important to practice good water hygiene to avoid incorporating oil, dirt, or chemicals into your spa.

Remember to take a shower before you jump into the spa, avoid using sunscreens or lotions, and make sure you are not dragging dirt or dust into the spa.

We also recommend using swimwear specifically for using the spa and avoiding washing it with detergent or soap to prevent contaminating the spa water.

What causes black flakes in my spa?

If you notice black flakes instead, you are likely dealing with mould. This biofilm may also be caused by mildew, bacteria from human skin, oils, soaps, moisturisers, sunscreens, dirt, grime, and other things that have built up over time.

The best way to counter black flakes is by doing a thorough cleaning of your jets. Learn more about in this in the detailed guide on how to remove, clean, or replace spa jets.

How do I get rid of pink mould in my spa?

Follow these steps to remove pink or green mould in your spa.

Step 1. Empty spa

To deal with pink or green biofilm in your spa, first, empty your spa. Read the detailed guide on how to drain and refill your spa.

Step 2. Clean spa

Using commercial grade cleaner and degreaser, wipe around the headrests and jets. We recommend Spa Safe Pipe Sanitizer which is effective in removing bacteria, fungus, mildew, moulds, and mites in pipes.

In case your spa uses the Purezone Filter, make sure to remove them from the spa before using Spa Safe.

Step 3. Use algaecide

Once the spa is clean, refill the spa with water and use an algaecide to completely get rid of any remaining algae. We recommend using Poppits® Pool Algicide Conditioner and Clarifier. Make sure to follow the proper dosage instructions to achieve crystal clear water and get rid of algae.

How do I prevent algae in my spa?

Getting rid of mould and algae is just the first step. To protect your spa from future algae build-up, it’s vital to take preemptive steps that will help avoid algae from coming back and affecting your spa again in the future.

To learn more about algae, read the detailed guide on how to prevent algae in your spa and this article on why is my spa water green.

How to look after my spa water

Proper spa water maintenance is important for health, the durability of your spa, and a satisfactory spa experience. Our Water Care Guide contains thorough information on how to look after your spa water to keep it clean, clear and safe. For a better understanding of water care, read the guide below.

In Summary

White flakes or scaling in spas can be harmful to your spa shell and piping. Immediate removal is important to avoid causing permanent damage to your spa’s components.

It is also vital that you take steps to keep the white flakes from coming back. You can do this by ensuring that you are sanitising properly, cleaning filters regularly, and changing out the water every 3 to 6 months.

We also recommend following proper water hygiene to avoid the build-up of oils, dirt, and chemicals in your spa from the use of detergent, sunscreens, or lotions.

If you need more information about how to effectively sanitise or maintain your spa and what products to use, don’t hesitate to contact us.

Got more questions?

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DISCLAIMER The following registered trademarks and brand names are owned by companies not affiliated in any way with Spa World™ or Vortex Leisure Pty Ltd – the parent company of Spa World Ltd: BioGuard Aquality Balancer is a trademark of BioLab Australia Pty Ltd. Zodiac Spa Pipe Cleaner is a trademark of Fluidra Group Australia Pty Ltd. Poppits® Pool Algicide Conditioner and Clarifier is a trademark of Waterco, Inc.

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