Your swim spa – the one place you go for so many different things – tranquility, peaceful relaxation, vigorous exercise and fun with friends and family.

But wait – what’s that? Cloudy water?

Don’t stress, cloudy water is a common problem in swim spas. And it’s fixable. Follow our simple steps to restore your swim spa water’s clarity and get back to all the versatility your swim spa offers.

But first, why is your swim spa water cloudy, hazy or lacking its usual clarity? Knowing the causes can help you learn how to avoid them in the future.

Common Causes for Cloudy Water

1. Unbalanced Water:

Fluctuations outside ideal water balance parameters for a swim spa can result in cloudiness.

2. Low Chlorine Levels:

Sufficient chlorine levels are essential for proper water chemistry. Insufficient chlorine levels can lead to bacterial growth and cloudy water.

Close up shot of the edge of a swim spa. It features the jets and swim spa seats.

3. Poor Filtration:

Dirty filters or filters that are old, worn or torn won’t do their job well. Effective filtration helps remove debris, dirt and other contaminants from the water. Without adequate filtration, buildup occurs and causes cloudy water.

4. Organic Matter:

This covers a host of things from leaves, small bugs, branches, and dirt to the accumulation of sweat, lotion, oils and sunscreen. You may not even realize the buildup until you see cloudy or hazy water in your swim spa.

Keep organic matter – leaves, twigs, dirt – out of the water. Shower before using the swim spa so that lotions, oils, or sunscreen don’t build up in the water.

Clip art of two swim spa water droplets. They are shaded in great and blue tones.

5. Phosphates:

The water could be full of phosphates. Phosphates are naturally occurring compounds found in many water sources. You can’t see them in the water, and they don’t show up on test strips. They can discolor your water, and worse, they are “food” for algae.

6. Source Water:

That’s the water you fill your swim spa with. It could be full of phosphates, or it could be high in metals; both can cause cloudy water. Take a water sample to your local retailer. If it’s high in metals, they can recommend a metal out product.

7. Biofilm:

Biofilm is made up of living, reproducing microorganisms, like bacteria. They make a sticky substance that holds them together and can develop over time inside components of your swim spa. That means you can’t see the buildup, you can only see the result: cloudy water that’s hard to manage.

Now that we’ve identified the potential causes of cloudy water, these 8 steps will help you restore water clarity:

8 Steps to Clear Up Cloudy Swim Spa Water

1. Weekly Test, Monitor and Adjust Total Alkalinity and pH Levels

Water balance is essential to clean, clear water. Test the water regularly to ensure that the water parameters are within ideal levels (always test and adjust Total Alkalinity first, before pH):

Total Alkalinity 80 – 100 ppm

pH levels 7.2 – 7.6.

Water test strips sit on a white towel with water in the background.

Use Total Alkalinity or pH increasers or decreasers to get your Total Alkalinity or pH within range.

Total Alkalinity and pH levels outside of this range contribute to water cloudiness and other water chemistry issues.

Keeping water balanced will also help the sanitizer you use be most effective.

For more information on balancing your swim spa water, check out FROG’s  Water Balancing Guide for Swim Spas. You’ll find a step-by-step process to help you get your water balanced.

Closeup shot of the back of the FROG @ease yellow test strip bottle. There are testing color ranges for various levels.

2. Check Your Sanitizer(s)

Check your sanitizer levels to make sure they are within ideal range.

The Center for Disease Control (CDC) recommends free chlorine concentration of at least 1.0 – 3.0 ppm in hot tubs/swim spas.1

If you use dichlor in your swim spa, test to make sure your chlorine level is between 2.0-4.0 ppm. Adjust as needed.

Mother plays with her two daughters in a swim spa with FROG @ease in the background.

However, if you use an EPA registered sanitizer that combines a low level of chlorine and sanitizing minerals, like FROG® @ease® Sanitizing System for Swim Spas, you’ll use up to 75% less chlorine*, and keep chlorine levels between 0.5 – 1.0 ppm.

FROG @ease uses SmartChlor®, a unique, proprietary type of chlorine, that works with FROG Minerals; together, they kill bacteria 2 ways.

Plus, using less chlorine means water feels softer, swimsuits don’t fade and surfaces are protected.

The Mineral Cartridge works together with the SmartChlor Cartridge to create Fresh Mineral Water® in the swim spa – using much less chlorine, keeping chlorine levels consistent and water feeling soft.

If you use FROG @ease in your swim spa, check both Cartridges regularly and replace when needed.

An added benefit: you don’t have to keep adding chlorine. Each silver SmartChlor Cartridge lasts 3-4 weeks.

The blue Mineral Cartridge lasts 4 months – if yours is 4 months old or older, it’s time to replace it.

Together, the two Cartridges play a crucial role in maintaining water that’s clean, clear, and feels soft. Replacing them is quick and easy, and they keep a consistent level of chlorine in your swim spa at all times, so it’s ready when you are!

3. Clean Filter Cartridges Regularly

Maintain clean filter cartridges in your swim spa to ensure filtration and prevent the accumulation of debris and contaminants.

Regularly remove, rinse or clean the filters and backwash as needed to remove trapped particles. And replace old, worn or torn filters.

Man's hands pull a filter out of a swim spa's interior.
Water circulates in a swim spa. The water feature is turned on and featured in this image.

4. Maintain Continuous Water Circulation

Circulate your swim spa water continuously until clarity is restored. Proper water circulation promotes effective filtration and chemical distribution throughout the swim spa. As a result, suspended particles are eliminated, and water clarity improves.

5. Use a Metal Out or Phosphate Remover

Bring a sample of your water to your local retailer. If they find it’s high in metals, they’ll recommend a metal out product.

If they find it’s full of phosphates, they’ll recommend a phosphate remover. That means no “food” for algae, and no opportunity to discolor your water.

Both will correct the source of what’s causing cloudy water and clear it up.

6. Shock the Water

Shock the swim spa water to eliminate organic contaminants, bacteria and algae that contribute to water cloudiness. Use a shock treatment product and follow the manufacturer’s instructions for dosage and application.

We recommend FROG Maintain® for Swim Spas. It’s a single dose maintenance shock that’s easy to use.

A packet of FROG Maintain sits outside a box full of the product.

Cut open, pour in and 15 minutes later your swim spa is clean, clear and ready for you! No measuring, no mess, no guess!

7. Use a Clarifier

Consider using a clarifier that removes suspended particles to clear up your swim spa water. Clarifiers work by coagulating tiny particles, so they are easier to filter out of the water. While clarifiers provide temporary relief from water cloudiness, they don’t address underlying water chemistry issues and should be used in addition to our other steps.

8. Consider Draining and Refilling

If cloudy water persists, it may be time to drain and refill your swim spa with fresh fill water. Draining and refilling the swim spa can help to remove accumulated contaminants and restore water clarity.

It’s generally recommended to drain your swim spa every 3 months, however, there isn’t a set time limit. Consult your swim spa dealer for guidance on the recommended frequency of draining and refilling based on your swim spa use and water care habits.

If draining and refilling – bring a water sample to your local retailer to check for Total Hardness and phosphates – clear up potential issues in your source water before you refill.

And while you’re at it, consider purging  your swim spa.

A man refills a swim spa with a green garden hose.

9. Purge

If you’ve never purged your swim spa, it may be time. Your swim spa has jets and many internal components that need to be regularly cleaned and maintained. Ask your dealer for recommendation of a purge product.

Cleaning prevents bacteria or other harmful microorganisms from building up, and causing cloudy, hard-to-manage water. See our article on purging, it takes time but it’s worth the end result of clean, crystal clear water that’s effectively sanitized.

Cloudy Water Cleared!

Now that you’ve followed these steps, your swim spa water is clean, clear and ready for action!

If you need additional help, check out the FREE FROG Water Care App It offers help and resources 24/7. Download it now for free!

Or, contact your local swim spa retailer – they are always ready to help.

If you have questions about FROG products to sanitize your swim spa, call our Customer Service Department at 800-222-0169 Mon-Fri 8-5 Central, email us at or ask a question on the Ask FROG Chat box on our website.

Here’s to having fun, working out, and relaxing in your crystal clean, clear swim spa!

A woman in a yellow swimsuit and sunglasses relaxes on a pool floatie in the swim spa. FROG @ease is featured as it floats in the water.
*Compared to the minimum ANSI recommended bromine or chlorine level of 2.0 ppm for a swim spa

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