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How to Fix Cloudy Hot Tub Water (causes & solutions)

It’s a sad sight to get home to cloudy hot tub water at the end of a hard day. Or maybe it’s been that way for a while? So how do I get my hot tub water clear again?

To clear up cloudy hot tub water:

  1. Check and adjust the pH
  2. Add 1/8 cup of hot tub shock
  3. Add those chemicals with the jets running
  4. In areas prone to hard water, add a calcium reducer
  5. Add a hot tub clarifier
  6. Drain and refill the water if it has been close or longer than 3 months

Hard water, low sanitizer levels, or a high pH are some of the main reasons for cloudy hot tub water. It’s a common problem. But the above is just scratching the surface…

In this article, we’ll do a deep dive into why your hot tub ends up with milky water and how to make the water clear again.  And be aware that non-chlorine shock will always produce cloudier water than chlorine-based shock.

What I’ll be sharing is based on my experience of having owned 4 hot tubs for over 15 years.

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.

hot tub clear again lg

Reasons Behind Cloudy Hot Tub Water

Hot tub water can become cloudy because of high levels of contaminants, TDS (total dissolved solids), bacteria, low sanitizer level, high pH and dirty or clogged filters.

Let’s check out some of these causes in some detail.

1. The presence of contaminants

As people use the tub, they unwittingly leave residues of make-up, lotion, sweat, shampoo, body oil, urine. Individually, they aren’t much. But collectively, these small particles can dirty the water and clog the filtration system.

Since hot tub water is often used for about 3-4 months before being changed, it’s not surprising that contaminants (and I only mentioned a few) make the water cloudy.

You might be wondering why the sanitizers, alone, couldn’t prevent the cloudiness. At times, contaminants bind with the sanitizers, reducing their efficacy. They are simply too much for the sanitizers.

2. Unbalanced water

Besides adding appropriate levels of sanitizers and shocking the tub, ensuring that the tub water is balanced is vital to keeping it clear and clean.

So, when the water becomes unbalanced, it can turn cloudy. Balancing the water is vital because it also affects how effective sanitizers are.

If the water is not balanced, the sanitizers do not work well, and you end up with cloudy spa water.

3. Low sanitizer level

Ensuring adequate sanitizer levels is one of the pillars of having a hot tub that’s clean, clear, and safe. Sanitizers are arguably the most vital factor in having pleasant soaking experiences.

So, when their level is too low, the water turns cloudy.

So at least once a week, dip a test strip in checking for total alkalinity, pH, and chlorine levels (or bromine). Poor water chemistry can definitely lead to murky water.

Luckily these simple steps will get you clear water in no time.

4. Dirty or clogged filters

Over time, your filters can become dirty or clogged with debris, such as the remnants of soap, oils, and lotion. These could consequently reduce water flow and put a strain on your pumps resulting in cloudy water.

Proper circulation helps maintain the health and color of your water. When it’s moving freely, it can easily be filtered, and the sanitizers can also do their work.

When this is not the case, the water becomes cloudy.

Give your filters a rinse every 3 weeks right at the kitchen sink with a sprayer and hot water. Gently pull apart the folds to get into each pleat.

Then every 3 months do a chemical soak with a good filter cleaner like Spa Depot’s Power Soak from Amazon.

5. High level of Total Dissolved Solids

If the water is old, it can accumulate Total Dissolved Solids (TDS), making the water cloudy. What are they?

TDS are a measure of all the matter (such as minerals and chemicals) that are present in the water. A keyword to understanding TDS is “dissolved.”

So, it refers to substances added to the water that has dissolved in it. Residues of oil that can still be seen do not constitute TDS.

I also devoted a recent article of mine to explore the causes of cloudy and smelly water. And how to fix it. Ironically there’s one thing we almost all do in our hot tubs that can lead to stinky water.

Just click the link to read it on my site.

Steps to Clarify Cloudy Hot Tub Water

Cloudy hot tub water can put a damper on your relaxation time. Here’s a quick roadmap to clarity.

First, check and clean your filters. Dirty filters can be the prime culprits behind murky water. Next, test the water’s chemical balance. Imbalances in pH, alkalinity, or sanitizer levels often result in cloudiness. Adjust as necessary.

Third, consider shocking the water to remove organic contaminants. Use a hot tub-specific shock and follow the recommended dosages. If hardness is an issue, employ a calcium reducer. Finally, if all else fails, it might be time for a full water change. A fresh start can sometimes be the most efficient solution.

With these steps, you’ll be on your way to crystal-clear hot tub bliss.

But you can also use a hot tub clarifier!

This simply causes all the tiny particles of dirt, debris, and oils to be combined so they are large enough to get caught in the filters. Left alone, they are often so small they pass right through the filters.

Add up to 8 oz. to clear the water now, and then add a small amount each week to maintain it.

CLICK HERE to see my favorite clarifier on Amazon.

Milky Appearance in Hot Tub Water

Milky water in a hot tub can be both puzzling and concerning for owners.

It’s an indication that something’s amiss, be it with the chemicals, contaminants, or the equipment. While the milky consistency might look off-putting, with the right understanding and steps, you can restore the pristine clarity your hot tub deserves.

Dive into the sections below to get a grip on the causes and solutions for this common issue.

Causes of Milky Hot Tub Water

Milky hot tub water can result from several culprits.

First up, imbalanced chemicals. Too much calcium or high alkalinity can cause water to turn cloudy. Overused or outdated sanitizers, like bromine or chlorine, might not be effectively killing bacteria and other contaminants.

Speaking of contaminants, lotions, cosmetics, and even natural body oils can introduce particles into the water, leading to a milky appearance. Then there’s the equipment. A worn-out or clogged filter can’t effectively trap and remove tiny debris from the water.

Additionally, if the hot tub water hasn’t been replaced in a while, accumulated dissolved solids might be the issue. Finally, sometimes the cause can be environmental – think pollen, dust, or other minuscule debris blowing into the tub. Identifying the exact cause can require a bit of detective work, but once you pin it down, clearer waters are on the horizon!

Solutions for Milky Water in Hot Tubs

Start by balancing your hot tub’s chemical levels.

Test the water’s pH, alkalinity, and calcium hardness, and adjust as needed. Remember, balanced water isn’t just clearer; it’s kinder to your skin and equipment. Next, give those sanitizers a check. If they’re old or insufficient, it might be time for a change. Regularly clean and, if necessary, replace your filters.

A fresh filter can work wonders in trapping those pesky particles.

Had that water in the tub for eons? Consider a full water replacement to get rid of built-up contaminants. Also, before diving in, give yourself a quick rinse to wash off lotions and cosmetics. And hey, if you’re in an area with a lot of pollen or dust, a cover can be your best friend.

With these solutions in hand, you’ll be on your way to crystal-clear relaxation in no time!

Issues with Foamy Hot Tub Water

Foamy hot tub water is a common concern for spa owners.

Often an indicator of water imbalance or contaminants, this foaming can diminish the relaxing experience of a hot soak. From the residues of personal care products to imbalanced chemicals, various factors can lead to this issue. Addressing these causes is essential for a clear, inviting hot tub.

Underlying Causes of Foamy Hot Tub Water

Foamy hot tub water often arises from specific underlying issues.

One primary cause is the presence of oils and lotions introduced by bathers. These substances react with the water, especially when jets are activated. Residual detergents on swimwear can exacerbate the foaming – highlighting the importance of thoroughly rinsing swimsuits before use.

Water chemistry is another significant factor. Imbalances in pH, alkalinity, or sanitizer levels can promote foam formation. Additionally, using old or poor-quality water can contribute to this issue. Regular water changes and careful maintenance are key to prevention.

Fixing and Preventing Foam Formation in Hot Tub Water

Foam formation in hot tubs can be both a nuisance and a sign of underlying water quality issues.

To fix and prevent this foam, start by testing and adjusting water chemistry. Ensure that the pH, alkalinity, and sanitizer levels are within recommended ranges.

Regularly using a spa defoamer can provide immediate relief, but remember, it’s a temporary solution. Rinsing off personal care products before entering the tub minimizes contaminants that contribute to foaming. Cleaning and replacing filters on schedule can also prevent foam, as dirty filters may reintroduce impurities. Finally, consider a complete water change if foaming persists.

Regular maintenance, combined with mindful usage, can keep your hot tub foam-free and ready for relaxation.

Maintaining Proper Chemical Balance in a Hot Tub

Maintaining the right chemical balance in your hot tub isn’t just about clear water; it’s crucial for the overall health of the tub and those using it. An imbalanced tub can be a breeding ground for bacteria and lead to issues like cloudy water, skin irritation, and equipment damage.

By keeping everything in check, you ensure a safe and enjoyable soak every time.

Importance of Water Balance in Hot Tubs

Cloudy or foamy water is also triggered by high pH.

So, you’ll need to balance your pH and alkalinity levels. Use test strips and aim for a balanced pH between 7.2 – 7.8 parts per million. You never want to go above 7.8. If you do, the water will turn cloudy.

Addressing Low Sanitizer Levels

Sanitizer is the most important factor in having a healthy hot tub. It helps purify and kill bacteria. Sanitizers come in two main types: chlorine or bromine.

That being said, there are also some enzyme-based alternative ones for those sensitive or allergic to chlorine or bromine.

Chlorine is the most widely used sanitizer for pools (it’s also used for tubs). However, because it doesn’t hold up to heat well, I’m not much fond of it for hot tubs.

Bromine is the most widely used sanitizer for hot tubs. It comes in tablets, powder, or liquid. I prefer tablets in a floater as I can set it and forget it.

If an appropriate level of sanitizer is not added, bacteria and contaminants can grow in the water. Not only can this lead to cloudy water, but it can also be unsafe to soak in.

A helpful hint: Make sure you add sanitizer a few times a week, depending on how often you use the tub.

Curious about what happens if the level of chlorine is too low? 

That’s what I explored in some depth in a recent article of mine. I explained that bacteria and contaminants grow in the hot tub water when the level of chlorine is too low.

Just click the link to read it on my site.

Dealing with Hard Water and Scaling in Hot Tubs

Hard water and scaling in hot tubs aren’t just eyesores; they can damage equipment and reduce efficiency.

Managing these issues is crucial to extending your tub’s lifespan and guaranteeing a smooth soak. Dive deeper to understand the causes and get top-notch solutions.

Understanding Calcium Hardness in Hot Tubs

Calcium hardness in hot tubs refers to the amount of dissolved calcium in the water.

Why should you care? Well, too little calcium can lead to corrosive water, harming your hot tub’s equipment and shell. On the flip side, too much calcium results in scaling—those unsightly white deposits that form on surfaces.

This scaling not only affects the appearance but can also clog filters and reduce the efficiency of heaters. Ideally, calcium levels should be maintained between 150-250 ppm. To achieve this balance, regular water testing is essential. Depending on the results, you can either add a calcium increaser or dilute the water to manage excess calcium.

Regular maintenance ensures your hot tub remains a place of relaxation, not a source of stress.

How to Address Scaling in a Hot Tub

Scaling in a hot tub can be quite the eyesore, not to mention its potential to clog filters and reduce equipment efficiency.

So, let’s tackle it head-on. First, test the water for its calcium hardness. If it’s above 250 ppm, you’re in scaling territory. Start by using a scale remover – simply follow the product’s instructions.

For prevention, consider a water softener or using products that prevent calcium buildup.

Regularly draining and refilling your tub helps too, especially if your area has hard water. Lastly, clean your filters frequently. A scaled filter won’t trap debris efficiently, further reducing water clarity. By addressing scaling promptly and adopting preventive measures, you’ll keep your hot tub in tip-top shape.

The Importance of Regular Shock Treatment in Your Hot Tub

Shocking a hot tub involves using a large dose of oxidizer to the water. Typically you’ll add about 1/4 cup of shock to a medium-to-large sized hot tub once per week.

An oxidizer is a chemical that acts on impurities such that they lose their electrons and hence break down more easily. Often the spa shock will be chlorine, which is fine even if your sanitizer is bromine. But non-chlorine shock is available too.

But the water will always be less cloudy if you use chlorine shock.

Shocking the water helps reactivate the sanitizer and removes bromamines or chloramines, which happens when the sanitizer breaks down.

This has the end result of making the water clear again.

How a Hot Tub Filter Can Cause Cloudy Water

Residues or larger particles of soap, body oils, body lotions, sweat, organic debris, detergent, and algae could clog and dirty a hot tub filter and lead to foamy hot tub water. So a clean filter is a must!

So, ideally, you want to rinse them regularly, about every 3 weeks. You can do this with your garden hose to keep them clean or at the kitchen sink if you have a sprayer.

Then you want to do a deep clean of the filters about every 3 months.

Effective Spa Filter Cleaning Techniques

To deep clean, I like to add some of Spa Depot’s Power Soak from Amazon to a 5-gallon bucket. Then I simply soak my filters for 1 hour in hot water.

You can also do a cold soak which is a little gentler, for 24 hours. But you should use a set of backup filters if you do that.

But even if you’re taking good care of your filters, there will come a time when they’ll need to be replaced. When you are really on top of filter maintenance, you can probably get away with replacing them with a new filter every 2 years.

But otherwise, about once a year is probably best.


We looked at the causes of cloudy water and how hot tub owners can fix it.

We learned that the presence of contaminants, unbalanced water, low sanitizer levels, and clogged or dirty filters are some of the reasons.

We addressed how dirty water can be made clear again.  

We also looked at whether it’s okay to use the tub if the water is cloudy. No. It’s not only gross; it’s a great way to pick up some infections.

We wrapped things up by considering the best way to clear up cloudy water: Drain the tub, wash it thoroughly, and refill.

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.

Frequently Asked Questions

Can I use my hot tub if the water is cloudy?

It is not advisable to use a hot tub if the water is cloudy. The cloudiness indicates that the tub is in an unsanitary condition with possible high pH and/or bacteria build-up, neither of which are safe.

When tub water is in good condition, it is crystal clear. But once it becomes hazy and difficult to see through, there’s a problem that needs to be fixed asap.

Apart from being unsanitary, cloudy water can be a great place to pick up some nasty infections. Would you consider jumping into a swimming pool with murky water?

I thought so.

In a previous section of the article, we checked out what to do when the tub water is cloudy. Shocking the water is one of the things you can do if you don’t want to drain and refill.

But how often should it be done?

Can you over-shock your tub water? Find out the ideal number of times in a recent article of mine. I get into how and when to shock, what kind is best and whether or not its needed right after a refill.

Just click the link to read it on my site.

Is draining and refilling my hot tub the best way to get clear water?

Draining and refilling a hot tub will eliminate most issues with high levels of TDS and calcium, bacteria, or unbalanced pH. However, it should not be necessary to do this more frequently than every 12 weeks. And draining alone won’t eliminate biofilm.

Sometimes bacteria build-up known as biofilm can accumulate inside the plumbing. And it will still be there after you refill.

For that reason, I do a biofilm clean out every time I drain and refill my hot tub.

I just get some of this Oh Yuk! Healthy Hot Tub Cleaner on Amazon, and pour it in and let it circulate for an hour before draining.

That eliminates the biofilm and ensures that new water is really crystal clear and free of contaminants. We’ve looked at various steps that can be taken to make water clear, and when executed properly, they are effective.

But, if the water is old, it’s best to simply drain the tub, wash it thoroughly, and refill it with clean water.

It would have to be balanced, tested, and hot tub chemicals would have to be applied.

If you’ve been using the water for a long time or a high number of people have been using the tub more frequently, it is probably better to simply go for the drain and refill option.

Still not quite sure about chlorine usage?

Can you use it every day? In a recent article of mine, I explored the “best practice” with regard to using chlorine. Chlorine does need to be added more often than bromine. But in most cases, daily will be too much. However, there’s 1 exception to that.

Just click the link to read it on my site.

Photo which requires attribution:

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

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Jeff Campbell