Skip to Content

How Long Does it Take for Cloudy Hot Tub Water to Clear?

By: Author Jeff Campbell

Posted on  - Last updated:

Categories Hot Tub Water Chemistry

There’s nothing less appealing for a hot tub’s water to be cloudy or murky. And while there are some easy fixes, how long does it take cloudy hot tub water to clear?

As a general rule, it takes an average of 24 hours for cloudy hot tub water to be restored to a clear state by either using a hot tub clarifier or by hyper-chlorinating the water. However, in severe cases, a drain, clean, and refill may be necessary. 

When a hot tub clarifier is applied to the water, it binds the small particles that trigger the cloudiness together so that they can be easily caught by the filter, rendering the water clear.

Over time, contaminants and microorganisms fill hot tub water, making it cloudy, smelly, gross, and unsafe. Several factors can trigger cloudiness. Fortunately, there are many effective ways of dealing with it.

In this article, we’ll explore how long it takes to clear cloudy hot tub water, whether chlorine can help, the causes of the cloudiness, and similar issues around cloudy hot tub water, and how to address the challenge.

Let’s dive right in…

Ready to Spend Less Time On Maintenance and More Time Enjoying Your Hot Tub?

Let’s face it. Balancing the water, cleaning filters, dealing with rashes, and trying to figure out which chemicals to buy and add can make you feel more like a chemist than someone who just wants to relax after a long hard day!

That’s exactly why The Hot Tub Handbook and Video Course is so valuable!

This is from Matt over at Swim University and he developed it for people looking to save money, time, and frustration. His tips on chemicals can save you $100/year just by making sure you buy only what you need.

So if you’re ready to stop being confused or frustrated with your hot tub and start spending more time in it, check out The Hot Tub Handbook and Video Course.

Just click that link to learn more on their website.

Sunsetting on the hot tub

Will chlorine clear up a cloudy hot tub?

As a general rule, a double-dose of chlorine-based shock will clear up a cloudy hot tub. This is because low sanitizer levels are one of the reasons the water has turned cloudy in the first place. The shock reactivates the sanitizer and restores clarity.

However, some people are sensitive to chlorine. So they can use non-chlorine-based sanitizers and shock. But that will almost always result in cloudier water.

Chlorine is a sanitizer.

So, it will help remove or at least destroy contaminants that triggered the cloudiness in the first place.

If the water is balanced and you’ve applied the right level of chlorine shock to it, the cloudiness will clear up in time. It shouldn’t take more than 24 hours for the water to return to a clear state. Shock serves to reactivate the chlorine and make it more effective.

So, can you apply chlorine to the hot tub water every day?

Not so fast, pal. Check out a recent article of mine where I shared the lowdown on the way to go. And, there are alternatives if you’re sensitive to chlorine or you simply don’t like the smell.

Just click the link to read it on my site.

Why is my hot tub always cloudy?

A cloudy hot tub can be caused by several factors such as low sanitizer level, too much chlorine, dirty filters, organic debris, algae, high calcium levels, and unbalanced pH, and/or alkalinity levels.

Let’s check out a few of the reasons.

Low Sanitizer Level

If the hot tub is being used a lot, the sanitizer level may become low because there are more contaminants in the water.

The solution is simple: Test the water, apply the right sanitizer dosage, and test again. Give it about a day, and the water should be clear.

Too High Alkalinity

Alkalinity is a measure of water’s capacity to neutralize acids and bases. In other words, water’s ability to resist acidification.

If the alkalinity level is too high, it could make the water cloudy (and may also trigger gastrointestinal challenges and skin irritation).

When the alkaline level is too high, it can cause carbonates, triggering cloudy water.

Contaminants

When a bather goes into a tub, a lot of products are being transferred off of their body into the water.

These include lotion, moisturizer, hair, make-up, fecal matter, urine, sweat, dirt… You get the picture.  These build up in and clog your jets, and they use up the sanitizer, making the water cloudy.

By the way, what happens if the chlorine level in a hot tub is too low?

I explained the consequences in a recent article of mine. Harmful contaminants can creep in, making the tub unsafe. Check it out to get the details.

Just click the link to read it on my site.

Is it safe to use a hot tub with cloudy water?

It is not safe to use a hot tub with cloudy water because it is a signifier of the presence of contaminants, which could be potentially harmful to those soaking. 

Hot tub water should always be crystal clear for it to be safe. So, cloudy water shows the presence of microorganisms and debris.

The cloudiness shows that the hot tub could be host to microorganisms that transmit infections and diseases.

What are some of these infections and diseases? 

They include:

  • Legionnaires disease
  • Skin rashes
  • Gastrointestinal issues
  • Eye and ear infections
  • Pneumonia
  • Cryptosporidium
  • Norovirus

(source and source and source)

You’ve heard of shocking a hot tub, right? But do you know how often it should be done? 

Interestingly, that’s the theme of a recent article of mine, where I explained that ideally, it should be done weekly and that you might want to shock it more often if more than 2-3 people are using the tub more than 3-4 days per week.

Just click the link to read it on my site.

What does a clarifier do for a hot tub? 

Hot tub clarifiers are used to clear up cloudy water. They help collect small particles by combining floating particles together to where they are large enough to get trapped in the filters. They also help maintain hot tub pH balance.

Some particles that cause cloudiness are so small. Clarifiers grab and stick these particles together, making them big enough for the filters to catch them.

So clarifiers help filters to become better at what they do. 

The particles that could easily have slipped past the filter are bound together by the clarifier. It makes them big enough to be trapped by the filter.

Spa Essentials from Amazon is the clarifier that I use and recommend. It clears cloudy, hot tub water by collecting small particles so that they’re now big enough for the filter to deal with them.

It helps to improve filter efficiency and also helps with the water’s pH balance. It’s got almost 200 ratings, and most are 5 stars.

CLICK HERE to check it out on Amazon.

How long does a hot tub clarifier take to work?

A hot tub clarifier will clear cloudy water fully within 24 hours. But small differences will be noticed almost immediately. As a preventative, add a small amount weekly for continuously clear water.

Say you’re having a party on Saturday, you’d want to apply it on Thursday so that it’d be ready by Friday.

Or, better still, apply it on a Wednesday. If it’s not yet as clear as you’d like, you can repeat the process. Make sure that you’re cleaning the filter after each use of the clarifier. After all, the clarifier makes the filter work better. So, the filter can catch some debris.

Make sure you give it a thorough cleaning. Clarifiers should be used once a week, and expect the water to be completely clear 24 hours later.

Again, Spa Essentials from Amazon is the clarifier that I use and recommend.

Does non-chlorine shock cause cloudy water?

Non-chlorine shock does not create crystal clear water to the same degree that chlorine-based shock will. While chlorine can be a little harsher on the skin, it also does a much better job with water clarity, clearing up a chemical imbalance, and creating clear water faster and more efficiently than non-chlorine shock.

So how does non-chlorine shock differ from chlorine shock?

Non-chlorine shock uses oxidization to clean the water instead of sanitization. So while it still breaks down contaminants, it doesn’t actually kills bacteria.

And high levels of bacteria, among other issues, can cause cloudy hot tub water. So for that reason, I prefer a chlorine-based spa shock.

Will a dirty hot tub filter cause cloudy water?

Yes. A dirty hot tub filter can cause cloudy water as it will be far less effective at trapping dirty, debris, body oils, body care products from the skin, hair products, and other contaminants in the water.

It can also affect the water flow into the pump and heater. And if it gets too clogged, it can reduce the water flow into the heater to such a degree that the high-limit trip switch gets tripped and your heater will shut off.

So a clean filtration system is hugely important not only for removing organic matter and clearing cloudy spa water, but also to keep your equipment in good working order.

A clean filter is a must!

Filter cleaner should be used on your cartridge filter about every 3 months, but you should also be rinsing your filters every 3 weeks and then changing them every 12-24 months depending on overall usage of the hot tub and how good a job you do on filter maintenance.

Does total alkalinity cause cloudy hot tub water?

Total alkalinity (TA) measures the ability of the water to neutralize acid. pH, by comparison, measures how acidic (lower number) or alkaline (higher number) your water is.

And if your TA is off, you’ll likely never get your pH balanced.

That being said, high alkalinity, as with high pH, can cause cloudy, milky water. So always balance your alkalinity after every water change, and after periods of high use.

Then, once TA is good, adjust the other chemical levels weekly such as pH level of the water and free chlorine (or bromine).

Will a high calcium level cause cloudy hot tub water?

Yes. Hard water, also known as water with high levels of calcium in it, can lead to cloudy water issues. High calcium hardness can also lead to scale buildup in the plumbing and equipment.

Now soft water can be just as bad. So ideally you want something in between.

Many of us have water softener systems, but they don’t always include the exterior hose spigots. So if you notice scale build-up around your hot tub, you will want to use a calcium reducer like this one on Amazon from MAV AquaDoc store.

It’s an easy fix for a common problem.

Conclusion 

Cloudy water is not your friend. That’s the truth.

It’s indicative of the presence of a problem that could be triggered by several factors.

In the article, we explored some of those factors. We also checked whether chlorine can help clear up cloudy water and whether it’s safe to go ahead and use a hot tub when it’s cloudy.

It is not. Lastly, we checked out hot tub clarifiers. What they do and how long they take to get clean water back in your hot tub.

Ready to Spend Less Time On Maintenance and More Time Enjoying Your Hot Tub?

Let’s face it. Balancing the water, cleaning filters, dealing with rashes, and trying to figure out which hot tub chemicals to buy and add can make you feel more like a chemist than someone who just wants to relax after a long hard day!

That’s exactly why The Hot Tub Handbook and Video Course is so valuable!

This is from Matt over at Swim University and he developed it for people looking to save money, time, and frustration. His tips on chemicals can save you $100/year just by making sure you buy only what you need.

So if you’re ready to stop being confused or frustrated with your hot tub and start spending more time in it, check out The Hot Tub Handbook and Video Course.

Just click that link to learn more on their website.

Photo which requires attribution:

Sunsetting on the hot tub by Nick Webb  is licensed under CC2.0 was cropped, edited, and had a text overlay added.

As an Amazon Associate, I may earn a small commission from qualifying purchases if you click on Amazon from my site and choose to make a purchase. You can read my complete affiliate disclosure for more details.

Jeff Campbell
Latest posts by Jeff Campbell (see all)