How To Fix A Cloudy Hot Tub?


Why is the water of my hot tub cloudy? Is there a way to fix this? We have heard these questions, not once but a thousand times.

If you are a spa owner, milky water is one of the problems you may have to deal with at some in your life. But this doesn’t mean that it can’t be prevented. If you follow the tips laid out in this article, you will be able to avoid cloudiness in your water and fix it when it occurs.

We all want to bathe in sparkling clean water. Best thing? Maintaining a clear spa is relatively simple. All you need to do is come up with an effective hot tub maintenance routine and stick to it.

Cloudy spa water is sometimes a result of negligence. If you care for your tub properly, you will be able to solve this problem even before it starts. So, let’s find out what gets your hot tub water murky in the first place.

Reasons Why You Have A Cloudy Spa

The ideal hot tub temperature is between 36 ˚C and 38 ˚C. Scientists argue that this is the perfect breeding temperature for disease-causing pathogens.

Even though these are just one of the many things that can make your water look cloudy, if your hot tub chemistry isn’t right, you might have bigger problems to deal with in the future like replacing the parts of your tub or the entire system. The major causes of cloudy hot tub water include:

1. Dead Leaves And Algae In The Hot Tub

Where you put your hot tub matters a lot when it comes to keeping it clean. If your spa is located outdoor, you will need to constantly be on the lookout for dead leaves, dead insects, grass clippings, bird droppings, and other natural matter that may get into the water and contaminate it.

If these get into your hot tub in large volumes, your sanitizer will have to work extra hard to break them down. Remember, you add chemicals to your equipment based on the amount of water it holds but not the number of contaminants in it. What this simply means is that your sanitizer may not be able to kill all the bacteria, which would result in milky spa water.

Letting these contaminants invade your hot tub may also block the filter and the circulation system. As this dirty deteriorates, your equipment stops working efficiently and you end up with cloudiness in your water.

To keep debris away from your water, invest in a hot tub cover, and keep the spa covered whenever it is not in use. A cover will serve as a dual-purpose glider – it will protect your tub and retain its heat.

Another contaminant that threatens the sparkle in your water is algae. This one grows in a hot tub due to poor water chemistry. Both algae and substandard water maintenance can cause cloudiness in your water. The best way to get rid of algae in your water is by shocking your hot tub to maintain efficient circulation.

2. High Concentration Of Metal In Your Spa Water

How did you refill your hot tub when you set it up? Did you connect a hosepipe to the tap in your garage and let the water flow till the hot tub was full? This could be the reason why you have a cloudy hot tub!

If the source of your household water has a high concentration of metal, it could mess up with your water chemistry wreaking havoc on your spa. While “metallic water” will be just fine in things like cooking, cleaning, and laundry, it could be a death sentence to your expensive spa. It can corrode and stain the components of your spa, leading to cloudy water or even a hot tub tripping breaker.

To get rid of metal contaminants in your water, use a hose filter. This will keep your tub protected from cloudiness.

3. High Bather Load

If you recently had a few friends over and all of you ended up in your hot tub but didn’t sanitize it or give it a shock dose the following day, you and your buddies could be the reason why your water is cloudy. Okay, maybe you added your sanitizer buy it wasn’t enough to deal with the high amount of contaminants left behind by the bathers.

Just as the increased load your spa has to keep up with, your sanitizer also has to deal with the foreign substances that have been introduced into the water. These are things like shampoo residue, body lotions and sunscreens, soap residue from the swimsuits, and other filthy stuff from human bodies. Did you know that some bathers even answer their call of nature right there in the tub? Yuck!

If you are getting cloudy spa water after heavy tub use, the first thing you need to do is treat the water. And if you had added the sanitizers but the water is still milky, you should consider shocking your hot tub so that the water can have sufficient chemical levels to kill the contaminants.

4. Water Chemistry Problems

You can achieve your spa chemistry in a blink. But making sure that this balance is maintained all the time calls for hard work and dedication. If you skip your daily maintenance tasks for just a few days, your hot tub water could get murky.

When looking for hot tub chemistry-related problems, the first thing to check should be the PH of your water. How to balance the PH of your hot tub depends on how acidic or basic the water is. If the PH reads higher than 7.8 ppm, your water is too basic and you could end up with cloudiness. Bring the PH down to get things to normal.

The second thing to test would be the alkalinity. If the alkalinity of your hot tub water is higher than 120 ppm, your PH could get destabilized and the water could start forming scales. A combination of these two could make your spa milky. Lower the alkalinity to solve this problem.

Calcium hardness is also another factor to consider when maintaining balanced water chemistry. If your hot tub calcium hardness level reads below 175 ppm or higher than 250 ppm, you will need to bring it higher or lower to these levels to prevent cloudiness and scale build-up.

5. Hot Tub Plaque

Yap! Your spa is prone to plaque, just like poorly maintained teeth. The only difference is that this one is in form of a film.

A spa plaque is a sticky film that mostly covers the surface of your hot tub and its plumbing. Just like the teeth plaque causes cavities, this one wears out your spa surfaces and if not treated, or rather addressed in good time, you could find yourself budgeting for a new hot tub.

When this film attacks your spa, it makes the water look filthy and allows harmful bacteria like Legionella to breed. The biggest problem is that these bacteria use the film to protect themselves from disinfectants, which means your sanitizer alone cannot solve this problem.

6. Faulty Filter

If the filter of your spa is not working effectively, you could end up with cloudy spa water. The way your filter works is that it gets rid of large debris, elements, and contaminants that your treatments may not be able to break down.

Now, if your filter is clogged with dirt or not fixed properly, these contaminants will not be sucked into the filtration system and will remain suspended in the water. After some time, this dirt will slowly start decomposing leaving your spa water murky.

How To Bring Back The Lost Sparkle

Now that you know what could have caused that cloudy hot tub water, the next thing you need to do is fix this problem to avoid damaging your spa. There are several ways through which you can do this. Read on!

1. Give Your Filter A Thorough Cleaning

This is the first thing you do when you notice some murkiness in your spa water. Whether it is full of algae or clogged by human hair, if your filter is not working as it should, the water will let you know. Just detach it from the system and give it a thorough cleaning.

Depending on how dirty your filter is, you can decide to either rinse it or give it a chemical soak. If the damage is extensive, you may have to get a new one.

2. Get The Filter Running

Want to get rid of foam in your spa and fight that cloudiness? Have your filter run for at least 60 minutes, two times a day. If you use your spa quite often, you may want to run the filtration system more than this. Running the filter regularly clears dirt and debris from your equipment allowing your sanitizer to work efficiently.

3. Keep The Chemical Levels Balanced

We can’t insist enough on this, as poor water chemistry is the number one cause for water cloudiness. Get your test kit and find out what chemical levels need to be adjusted. Is it the PH? Calcium hardiness? Or Alkalinity?

Getting these levels right makes the difference between a clear, clean hot tub and a gross looking one. To maintain this balance, make sure to include water treatment in your spa care routine so that you don’t ever miss a chemistry date with your soaking spot.

4. Shock Your Hot Tub

Some hot tub bacteria and contaminants are stubborn and will not be contained by just adding a few drops of sanitizer into the water. Sometimes even when you add the recommended amount of treatment, these will not go away.

Think of something like spa plaque for a second. If you have this in your hot tub, your problem only gets worse because the bacteria you are trying to kill will just cover themselves with this slimy film and your sanitizers will not break any of their bones. Well, bacteria don’t have bones but you know what we mean.

Shocking your hot tub in such instances could be the only solution to your problem. As you will be giving it a higher chemical dose than usual, you will be able to break the film and find those hard to reach pathogens. Do this weekly and your water will immediately recover its lost glory.

5. “Kill” The Metals

If you are sure that the cloudy spa water is a result of a high concentration of metal in the water source, you will require some metal sequestrating solution. Unlike other reagents used in water chemistry, you only add these when you know for sure that you need them. The way these solutions work is that they mix with the metal and prevent it from oxidizing your spa water and causing discoloration to your tub.

The best time to add these will be when you do a hot tub set up and have filled your spa with filtered water. It should also be done after a spa flush.

6. Use A Clarifier

A clarifier is a special spa water treatment that joins the small dirt particles in the water together to form big ones. Since the particles have increased in size, they are sucked into the filtration system leaving the water clear.

Water clarifiers can be used once a week or twice depending on how often you use the hot tub. Also if you have had several bathers use the tub at once and suspect there might be some nasties in the water, you can clean these up before adding your shock treatment. If you are going to use this kind of treatment, make sure to give your filter a good rinse afterward to get rid of the dirt that has been removed from your water.

7. Drain Your Spa

We are assuming that you have been changing your spa water at least quarterly, so this should not be so hard for you. But if your water is still milky even after working hard on the tub, then you seriously need to drain and clean the hot tub.

When you empty the water from your spa, make sure it is clean before refilling it with water. Flush it if you must. Clean all the parts of your filter. Wipe the interior of your spa and check for signs of corrosion. Add fresh water and balance the chemicals to give your tub a healthy startup before hoping in.

8. Remove The Rust

If some components of your spa are corroded, the equipment and its water may discolor and those parts affected by the rust may not work efficiently. If corrosion attacks your pump, for instance, it may stop working completely and you may even have to replace it.

If your spa water passes through a rusted surface, it will lose its spackle and appear brownish or whitish. These are some of the effects of corrosion on your equipment and if not addressed early enough, you might have to deal with a bigger problem in the future.

Check all areas of your spa to see if the cloudiness is caused by a corroded component. If you find any rusted part, pull it out and get rid of the rust. A brush can get the job done. Find out where the rust is coming from in the first place and fix it.

9. Get Rid Of Algae

So your spa water is cloudy because some algae are blossoming underneath? Kick this out and you will get your water clear again. The only secret to doing this is keeping your tub clean and water chemistry balanced.

10. Contact A Specialist

If you have tried all of the above and you are still having murkiness in your tub, it may be time to get a professional to check your spa for you. Yes, this will cost you some bucks but who knows, they might just identify an underlying problem with your equipment. May be some parts need repair or even the whole equipment needs replacement.

How TO Avoid Cloudy Water In A Hot Tub

  • Take a shower (without soap)before hopping into the hot tub
  • Avoid using a detergent when washing your swimsuits
  • Clean hot tub filters regularly
  • Keep the water chemicals balanced
  • Stick to your hot tub maintenance schedule

Globo Surf Overview

“Prevention is better than cure,” they say. Taking good care of your hot tub is all your need to avoid cloudy spa water.

Although fixing a cloudy hot tub is not difficult, sometimes you may have all the issues we have discussed above working against you. Changing your water and giving your tuba a shock dose are just some of the ways to prevent your spa water from looking, feeling, and smelling gross. Hopefully, you will use other suggestions laid out here to sort out your murky water problem.

More Hot Tub Reviews:


  1. How To Fix & Prevent Cloudy Hot Tub Water,
  2. Cloudy, Milky & Foamy Hot Tub Water,
Globo Surf
My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!