Why Is My Hot Tub Cloudy? How to Fix It


A hot tub is easily one of the most enjoyable backyard additions, especially after a long day’s work. But when that crystal clear hot tub turns cloudy, it can be a big headache that could even make you sick. How can you fix it?

The are a few reasons why you may find your hot tub cloudy which are:

  • The sanitizer, pH, and alkaline levels need to be corrected
  • The filters themselves are very dirty
  • A lot of debris has fallen into the tub
  • It’s been used much more frequently than usual 

That’s the simple story, but troubleshooting a cloudy hot tub takes some more in-depth knowledge of how everything works. We’ll cover the common reasons your hot tub may be cloudy and how to fix it in more detail below.

Why Is My Hot Tub Cloudy? How to Fix It

What makes a hot tub cloudy?

When you get your swim trunks on (or not) after a hard day, the last thing you want to see is cloudy and gross water in your hot tub. It’s a headache, and the solution isn’t always obvious.

In order to help you properly identify the real culprit, we’ve put together more detail about all the different things that could be making your hot tub water cloudy.

Your hot tub “core” levels are all off

One of the most important pieces of good hot tub hygiene is making sure that the water has the proper levels of these three components:

  • Sanitizers like Bromine or a mineral agent
  • pH levels which need to be maintained within a specific range to disrupt bacteria growth
  • Alkalinity levels which, like pH, must be within a range

If any single one of these is out of alignment, it could lead to issues. 

Since your water is cloudy, the first thing to check is your sanitizer levels. Low sanitizer levels can quickly lead to a buildup of bacteria, algae, and just dead organic debris (like skin flakes!) that can make the water cloudy.

pH and Alkaline levels are typically not the main culprits for cloudy water, but you should check them too to be thorough. Besides, these levels all need to be checked often!

If the need to check the chemical balances in your hot tub is news to you, here’s a kit you can get to help you get started on this process.

Your mechanical filter is overloaded

Dirty hot tub filter
A very dirty filter

As opposed to a chemical sanitizer, mechanical filtration refers to the actual filter of the spa. It filters “mechanically,” i.e., just by straining larger clumps of debris or material.

Once you’ve ensured your sanitizer levels are all good, then pop open the filtration compartment and give your filter a quick check. If it’s full of gunk and debris, then it’s time for a quick clean or perhaps even replacement..

An excess of debris on your filter increases the amount of sanitizer your spa needs, quickly leading to low sanitizer levels and a buildup of gunk, causing cloudy water.

Your hot tub has seen more use lately

Hot tubs are meant to be shared, so it’s no wonder that they see an awful lot of people come and go in a day.

However, if you’ve recently had a party, company over, or anything else that resulted in the hot tub getting more use than normal, then it’s not uncommon to find cloudy water afterward.

It’s a little gross, and most people don’t like to think about it, but every person who gets in the hot tub is leaving behind:

  • Dead skin flakes that all humans are shedding, constantly
  • Any lotions or oils that they had on their body, even shampoos and conditioners
  • Sweat and other fluids that are a natural part of our bodies

Your sanitizer and filtration are set up to deal with this, but if it’s getting a sudden burst of people coming and going, then the water will cloud up from all the gunk it’s trying to filter. It may even have run out of sanitizer to deal with it all.

Can too much chlorine make water cloudy?

We briefly discussed that low levels of sanitizer could lead to cloudy water from all the stuff that isn’t being cleaned up, but it goes the other way, too.

High levels of any of the core chemical levels (sanitizer, pH, and alkalinity) can have effects that lead to cloudy water.

This is just another reason why it’s important always to keep an eye on your core chemical levels.

Hot tub water gets cloudy when jets are on

If your water looks clear or mostly clear until the jets come on, then the causes are likely the same.

To be clear, there will always be some foaming and cloudiness in the spa when the jets are on because of the air bubbles the jets introduce. However, if the water is cloudier, foamier, or has a different color than normal, then you need to stop and find the problem.

It’s rare for a cloudy problem to come from the jets themselves. The likelier reason the water looked clear beforehand is just that the debris and gunk had settled to the bottom, and the jets kicked it all back up into the water.

Is it safe to use a cloudy hot tub?

We know it can be a pain to have to do all of this maintenance when you just wanted a nice hot soak but getting into a hot tub with cloudy water may not be safe.

You could get hot tub rash, infections, burns from too much sanitizer, or any number of other issues. Don’t get in your hot tub until you figure out the source of the problem and fix it.

How to clear up a cloudy hot tub

cleaning a dirty hot tub filter

Now that we’ve gone over the main culprits of your cloudy hot tub water let’s discuss each one and how to fix it (along with some other tips).

Clear the tub of debris and clean the filter

If you haven’t been using a hot tub cover, now is the time to start. Never leave a hot tub uncovered when you aren’t using it, even just for a single night, or you will end up with all of this in your water:

  • Bugs, and lots of them
  • Bird poop
  • The urine or poop of whatever creatures decide to investigate your hot tub

That’s just to name a few. Not covering your hot tub will lead to the water being cloudy all the time—a serious health risk—and you’ll also spend lots more on sanitizers and clarifiers.

Fix any incorrect core levels

After just clearing visible debris, the next thing you need to do is run a test on your core levels. If any one of them is out of alignment, fix it by the appropriate method:

  • Sanitizer: If it is too low, add more to the recommended level. If it is too high, either remove some water and dilute it with freshwater or use Sodium Thiosulfate to neutralize some of it.
  • pH: If it is too high or too low, use soda ash or a pH decreaser, as the instructions on their packaging indicate. There are no shortcuts on this one!
  • Alkalinity: Same as pH, you will have to use an alkalinity increaser or decreaser

Keep in mind that pH and alkalinity treatments affect each other. Always fix the alkalinity first before moving on to pH. 

Try a shock treatment

Once you’ve tested the above three, and the water still isn’t clear, then it’s time for a good old-fashioned flocculant and shock treatment combo.

A flocculant simply binds all the smaller microscopic particles together so the filter can more easily pick them up. 

The shock treatment then comes in and, well, does exactly what it says. It chemically shocks any algae, bacteria, or other gunk to death so it can be cleaned up better.

Fixing cloudy hot tub water

When it comes to hot tubs, it can easily seem like there is a never-ending torrent of information to learn about pH levels, sanitizers, treatments, and so much more. When you’re faced with a problem like cloudy water, it’s hard to know where to start.

Thankfully, with a little know-how, it can usually be an easy problem to fix. Just check your core levels, clean the filters, and try a shock treatment. If nothing works hen empty the hot tub and refill.

Hot Tub Maintenance Course

I bought this course some months after I bought my first hot tub and was struggling with maintaining it. It was money well spent.

JP in Fuerteventura

I have had hot tubs for many years and a pool for the last 7 years. I had to learn how to clean it, maintain it and fix it the hard way. Since then I have helped many friends and neighbors with their pools and now I want to share everything I have learned with you.

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