Finally, How to Fix Cloudy Hot Tub Water Forever [August 2020]


We don’t usually pay attention to cloudy water until it happens. Finally, here is how to fix cloudy hot tub water in one take and don’t worry about it ever again.

If you want to fix your cloudy (milky looking) hot tub water, you will absolutely need to shock your hot tub with dichlor. For a 400-gallon hot tub, put in 4 tablespoons of dichlor with the pumps running in a clean cycle. Then wait for 15 minutes and measure chlorine. It should be 3-5 ppm. If it is not, try adding some more until it does.

One more note. Although it could look like a challenge, restoring your hot tub’s water back to its original clarity isn’t as difficult as one might think.

I also found some interesting cases when you actually don’t need to shock your hot tub because it might not be as cloudy as you think. Before that, let’s see why your hot tub gets cloudy and hot to avoid it in the future.

Bonus reading

Are You Also Having Issues With Mold, Mildew And Algae ?

Don’t worry about these. I have a full guide on how to fight it. And it wont take long before your hot tub is clean again. Check the top tips for mold, mildew and algae here!

Why Is My Hot Tub Water Cloudy And Foamy

Let’s check some of the most common causes of the cloudy and foamy hot tub water. 

Foamy Hot Tub Water

People Carry Stuff On Them

We use many chemical products throughout the day for our skin and hair and sometimes we forget to take a shower before we jump in the hot tub. Then over time, there happens to be a build-up of dead skin cells, lotions, oils, and hair sprays that end up in the water which becomes cloudy and foamy.

Particles From The Environment

Sometimes you simply forget to cover your hot tub after use. What then happens is that your hot tub water gets filled with all these different kinds of air contaminants. 

And it is not about the air being clean. It’s the small particles that you sometimes can’t see. For example, there are algae, pollen, and seeds that are flying around in the air all the time. If your hot tub is not covered, these things can accumulate in your hot tub and contribute to cloudiness.

Microbial Growth

Do you know who loves moisture? Bacteria and many other microorganisms. There are some bacteria that actually thrive at hotter temperatures such as the bacteria from the biofilm, a slimy substance that often shows up in hot water. As the biofilm builds up, parts of it break off into the water. All of this contributes to cloudiness in your hot tub.

Poor Water Chemistry

Poor water chemistry can also be a reason for your hot tub water becoming cloudy. How does this happen? The normal pH levels of water, which is an indicator of how alkaline or acidic your hot tub water is, in your hot tub is supposed to be around 7.8. 

When then happens is that the water becomes more alkaline (pH over 7.8), which causes cloudiness because of all of the accumulation of scale. In essence, scale contains calcium and other minerals that do not help against cloudy water.

Hot Tub Filter Issues

This one is simple. A dirty filter or a filter that was not installed properly can also cause water to look cloudy and foamy. The purpose of your hot tub filter is to filter your water and remove any particles that your sanitizing chemicals can’t. In case your filter has seen better days, then you should probably replace it since it will not do a good job of filtering your water and keeping it nice and clear.

Metals In Your Water

Assuming that you are using your tap water to fill your hot tub, make sure you check the water quality before you put it through your hot tub system. It is very much possible for it to have loads of metal in it that contribute to cloudiness. The trick to keep the metals out for some people is to use a hose filter when filling their hot tubs.

Poor Water Care

I can’t stress enough, but keeping good care of your water is essential. This includes using test strips to check alkalinity, draining and refilling every 60 to 90 days and not using the right water sanitizers. Without this, you are likely to face hot tub water that is cloudy and foamy.

Cloudy Hot Tub Water After Shock

If your water is looking cloudy immediately after shocking your hot tub water, know that it is a common occurrence for it to happen. Shocking your hot tub includes many different chemicals that are now reacting together. Your water clarity should return to the hot tub within just a few hours. Let it sit and don’t enter the hot tub until the chemicals even out.

In addition, I would double-check the hardness on your tub after shocking the hot tub is done. Too soft or too hard of water can easily cause the cloudiness to continue. 

One way to know this immediately is if the film/residue is chalky or not. If it is, then I would guess the water is too hard, and if it is slimy looking then you are too soft. 

I generally prefer my water on the higher side of acceptable, it tends to be less problematic. If your hardness is good, then check for excessive body care products like lotion or hair products that might be the culprit. These things usually wreck hot tub water pretty quickly and clarifier has a hard time consolidating oils. 

Hot Tub Water Cloudy When Jets Are On

This is the case I mentioned at the beginning of the article where I said that it might not be as cloudy as you think. Usually when we say cloudy, so far we have learned that is something negative and that we immediately relate to bacteria. 

There is something else that usually happens, which is the air in the water that makes it look cloudy. The general rule of thumb is that if it clears up after 15 minutes, that’s all it is. These new tubs mix an unbelievable amount of air into the water when the jets are on, so most of the time you have nothing to worry about.

Is It Safe To Get In A Cloudy Hot Tub

Is Green Hot Tub Water Safe ?

There are some people who still wonder if cloudy hot tub water is safe and whether the cleaning of the hot tub can be scheduled for another day. The answer is no, you should not leave another day go by before you give this some attention. 

Water can reach many places and if it is not 100% healthy, then it can easily cause a lot of infections. That being said, the water in your hot tub should always be sanitary and crystal clear. Any indication of it being different than crystal clean means that there is a problem. Cloudy water is typically the result of two things:

  • Chemical imbalance 
  • The result of bacterial growth

Either of these can pose a significant health risk. Start by checking the chemical imbalance first, as there might be a need for you to shock your hot tub water.

How Often Should Hot Tub Water Be Changed

For most users, the best time to change your hot tub water completely by draining it and refilling it back is around 3 to 4 months. There are also many users who claim to be getting 6 or months out a fill. This is where your usage comes in. You can easily tell if you have persistent cloudy water that requires constant shocking. Usually, if you get this far that means that you’ve gone too far and that it is time to change your hot tub water.

Now, here are more details for those who are not satisfied yet. 

Another way to tell when to refill is if you have persistently high levels of combined chloramines. You can test for this with a drop test kit (not strips, they are inaccurate). 

If the number is much above 1 (1.5, 2 or more), try shocking your hot tub to bring it down to 1 or less. It will certainly help if you maintain proper sanitization/oxidation practices. Your hot tub is a place of chloramines and other dissolved solids (aka bather waste) that can’t be oxidized. 

Eventually, what they do, is that they build up to a level that can’t be managed by normal sanitation/oxidation processes or by shocking your hot tub. In this case, the hot tub water will require more chlorine or bromine and will be difficult to maintain.  

This is the perfect time to drain and refill. When it comes to how much time it takes for you to follow this process, I can say that the amount of time for this to happen will vary. It is significantly affected by your hot tub size, a number of bathers, sanitizer/oxidizer application and how often you use it. 

It is also recommended that you do the CC test, which is a good way to indicate unseen problems. It will also indicate the overall health of the water.

To work out a more exact number of days between changes use the following:

To recap, if you see any of the following, it is a clear sign that you must change your hot tub water:

  • The water looks cloudy or tinted
  • You are adding too many chemicals
  • Algae growth
  • Scale build-up

Can Too Much Chlorine Cause Cloudy Water

Not really. If your levels of combined chlorine stay higher for longer periods of time, a cloudy hot tub might be the least of your worries.

Now, go back and test your water, if you haven’t already. Once you have your water tested, note your chlorine levels again. Usually, the lack of chlorine is one of the leading causes for cloudy hot tub water

The main purpose of chlorine is to sanitize the water from bacteria and other contaminants. Without it, the water can’t be sanitized and as a result, the contaminants in the water build-up which causes the hot tub water to become cloudy. So it is the other way around. Having less of chlorine makes it cloudy, and not when there is too much of it. Even though, having too much of chlorine is not good either since it generally affects the chemical balance of your hot tub water.

TIP: Over time, your chlorine level will diminish, and it turns into chlorine that no longer has disinfecting power. If this chlorine surpasses the amount of free chlorine in your hot tub, then really, you’re not adequately disinfecting your tub and you will need to shock your hot tub.  

What Is A Hot Tub Clarifier

We found that the most common cause of cloudy water comes from different contaminants in the water such as residual soap from swimsuits, hair & body or someone that uses body lotion before using the tub without showering and heavy use.

Each person using a hot tub usually sweats about a pint per half an hour of use. And this is where the clarifier comes to the rescue. If you try a clarifier, it will help in collecting small unfilterable particles into a larger mass so the filter can pick it up. As you know, some contaminants are too small for the filter to process, so it goes back into the hot tub. This way it gets eliminated for sure.

What Happens If You Put Too Much Clarifier In Your Hot Tub

Your clarifier is probably the easiest water chemical to overdose your hot tub water. Typically, hot tub water clarifiers attract colloidal matter in your tub (the things that make it cloudy) and glue them together while giving them more mass at the same time. 

Generally, the bigger the particle, the easier it is for your hot tub filter to catch and extract. 

Too much clarifier in the hot tub can act as a dispersant instead of a coagulant. That means it could easily do the opposite thing and completely ruin your hot tub water. Be careful not to overdose hot tub clarifiers, especially if you also use a metal sequestrant (Stain & Scale) product in your hot tub because it could cause staining.

Will Baking Soda Clear Up Cloudy Hot Tub Water

No, baking soda will not clear up cloudy hot tub water. It can just make things worse if you are not careful, and here is how. 

Baking soda is used to raise the alkalinity, not pH. It will raise your pH, but slightly. If your alkalinity is high it can cause hot tub water to become cloudy. On the other hand, sodium carbonate (not bicarbonate or hydrogen carbonate) is used to increase your pH levels, which can help with cloudy water. 

Related Questions

Why Is My Hot Tub Water Green and Cloudy

Some of the most common reasons for having green water in your hot tub are:

  • Algae
  • Excessive metal content
  • Low sanitizer levels
  • Low pH

Here are more indicators of why your hot tub water is green and how to deal with it:

If your hot tub water is green and the sides kind of feel slimy, chances are you have algae in your hot tub. You should fight algae with chlorine, shock, and cleaning the filter. 

Then if it’s green but the sides don’t feel slimy, then there are probably minerals such as copper or manganese in the water and the way to get rid of green hot tub water is by adding chlorine, shocking the tub and cleaning the filter.

If you are a frequent hot tub user, then make sure to put a little more chlorine more often since frequently using the hot tub can use up chlorine a little faster. Next, you want to keep your filters clean while adding appropriate shocks, sanitizers, and regulating your pH/alkalinity levels. You can prevent issues like this from popping up if you continue to be adding a stain and scale control solution as well as cleaning your filter more thoroughly with a cleaning agent. This way you are significantly reducing the chances of it happening again.

Editorial Staff

I'm Adnan Sabanovic, the guy behind Hot Tubs Report. I've had a chance to enjoy hot tubs last few years and have really become interested in owning one of them. Nearly every weekend you'll find me spending time with my family or playing sports. If I am not doing that then I'm here writing about tubs on Hot Tubs Report. This blog is a research for my first hot tub which I decided to document and share publically so others can benefit from it as well.

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