How to Fix Cloudy Spa Water

16 May, 2021

When it comes to maintaining your spa, cloudy spa water is one of the most common problems. Since spas have a low volume of water kept at high temperatures, this impacts the contaminants that come into the spa pool. These contaminants can be from nature such as leaves, or from spa pool users such as hair or body oils. It’s important to check your spa daily to avoid this and maintain proper hygiene standards as well. Forgoing proper spa maintenance can result in cloudy spa water.

Here are some reasons you might have cloudy spa water, and how to fix them.


If the level of sanitiser is low in your spa pool it can cause cloudy spa water. The sanitiser can be used up faster if there are contaminants in the spa as well. To fix this, check your sanitiser levels regularly and monitor them until the issue is fixed. To avoid build-up of unwanted substances inside the spa, you can use a spa pipe degreaser before emptying the spa water.


If the filters of your spa are old or dirty it can cause cloudy spa pool water. To clear this, you will need to change your spa filter. Remove the spa filters and rinse with a hose on low pressure or use a filter cartridge cleaner. It’s important to use a filter cartridge cleaner to clean the filters as it will help give it a deep clean. However, if you have a Purezone filter don’t use a filter cartridge cleaner, it should be replaced every 3 to 4 months. If the filters you’re using are over 12 months old, it’s time to replace them. It’s handy to have a few sets of filters that you can rotate around to ensure you’re not faced with this problem again.

Spa shock

If your spa pool has been highly used, contamination from perspiration, body oil, swimwear, and food can cause cloudy spa water. It’s important to use a spa shock treatment weekly (if used heavily) or after a big spa pool party. This will clean the organic contaminants that result in cloudy spa pool water. You’ll also need to check if you’re using a chlorine-free sanitising system. If you are then you’ll need a chlorine-free shock treatment.

Alkalinity or pH

High pH, alkalinity or total hardness being out of balance is another reason for cloudy spa water. To ensure it’s the right balance, check using your spa test strips. It should be between pH 7.2-7.8 and the alkalinity between 80-120. If the results show it’s not within these measurements you can change it by adjusting it up or down with an approved pH reducer or increasing the alkalinity. Low alkalinity and low sanitiser are also the cause of brown water.

Spa cover

If the spa cover is left on and smells when removed, this can also cause cloudy spa water. To fix this problem, clean all sides of the cover with a spa pipe degreaser, wash the cover and dry it outside in the sun. This will get rid of the smell and help you avoid cloudy spa pool water.

Check water

Depending on how long the water in your spa pool has been there it could be the reason for your spa pool having cloudy water. It’s important to check and dump the water regularly especially after periods of high or long usages. If it’s over 12 weeks old it’s time to dump the water. If it’s 2 to 4 weeks old, check the pH and alkalinity levels and also the filter cartridges. Metals in the spa water can also alter the water levels.

Track usage

Spa pools that are used daily or have a high amount of usage in a particular day or week can result in cloudy water. When you don’t have enough chlorine or bromine to sanitise your spa water it can cause cloudy water. If this is the case, use a spa shock treatment and add spa sanitiser after 4 hours. Also check that the spa cover is placed tightly over your spa pool. For extra safety, use a clarifier weekly and a filter cartridge cleaner.

Filler chemicals

Low quality, high filler chemicals could be the reason for your spa having cloudy water. Check the chemicals you have and ensure they’re high quality and right for your spa. To solve this problem, you’ll need to dump out all the water to get it fresh again.

Spa pump

It’s important to keep track of the amount of time the spa filter is running. If it’s not running for enough time daily then this could be the cause of cloudy water. To fix this, you’ll need to increase the amount of time that the spa pump operates in order to increase your filtering time. If the pump is on low speed this can result in low filtration. Try running it on high speed for a few hours each day. Running a pump only on low speed can also contribute to ineffective filtration. Run it on high for at least 2 hours every day. Also check if the pumps are being blocked by leaves, hair, or rocks and clear this out.


If your spa has cloudy green water, the reason for this is algae. Try using algaecide or chlorine-based shock product to kill the algae. Once this is done, check and adjust the high sanitiser levels. This should get your spa pool back to normal.


Particles of air and bubbles can also result in cloudy spa water. Low water and an air leak on the suction side of the pump can be the cause. Check your pipes and equipment regularly to avoid this. To fix the problem, you can seal it up with sealants or lubricants.
In most cases, dumping the water or shocking the spa pool can fix any issues with cloudy spa pool water. If you’re going to implement any of the fixes listed above, please make sure to check with your local spa dealer to make sure the fix is appropriate for your individual spa. If you’re looking for more information, check out Sapphire Spas FAQs to learn more about operating a spa, maintenance, and warranty. You can also call us on 1300 069 772 to get more information or advice on your situation.