Why Is My Hot Tub Cloudy? (And How To Fix It?)

If you’re a hot tub owner, then you know nothing feels better after a long day than relaxing in your own personal spa. But if your hot tub has cloudy water, then that relaxation is likely tempered by frustration and aggravation while you ask yourself “Why is my hot tub cloudy?”

Whether your hot tub is used regularly or just occasionally, the last thing you want is cloudy water. Not only does it look unattractive, but it can also be a sign of something more seriously wrong with your tub.

If your hot tub water is cloudy, you’re not alone. In fact, this is one of the most common issues hot tub owners face. There are a few different things that can cause your water to become cloudy, but thankfully there are also a few ways to clear it up.

In this article, we’ll explain why your hot tub water may be cloudy and offer some tips on how to clear it up. So if you’re suffering from cloudy water in your hot tub, read on for some solutions!

Related: Are Inflatable Hot Tubs Worth It?

Why is My Hot Tub Cloudy?

There are several possible causes of cloudy water in your hot tub, but they all relate to some sort of containment in the water. These particles or contaminants are typically too small to see with the naked eye and, of course, too small to remove by hand or with a skimmer.

Some of the most common causes of cloudy hot tub water include:

• Minerals in the water, such as iron, copper, and calcium
• Bacteria and algae
• Soap or other chemicals used in the hot tub
• Cosmetics debris (skin lotions, moisturizers, etc.)
• Dirt and dust
• Hard water

All of these contaminants can cause the water to become cloudy and even lead to more serious issues like bacteria growth.

Of course, skin lotions, moisturizers, and other cosmetics are often on your skin when you’re getting into a hot tub. You probably don’t think anything of it, but these products can easily cause the water to look cloudy. This is especially true if there are several people in the hot tub or if these types of products come in contact with the water frequently.

In the case of hot tubs left out in nature, there might not only be random bits of debris and organic matter in the water but it may also be infested by algal growth. These not only make the water cloudy, but they also make the walls and floors of hot tubs slimy and muddy by forming a film.

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Hard water refers to water with high amounts of calcium and magnesium ions. These cause the water to form a slimy residue when mixed with soaps and shampoos containing sulfate salts. The calcium and magnesium salts include a bulk of these depositions, and they also cause the water to get cloudy in long-term use.

It can be frustrating when in a situation where you ask yourself why is my hot tub cloudy? Knowing why it is becoming cloudy in the first place will help you to address and even prevent going forward.

Why Isn’t It Being Filtered Out?

As almost all quality hot tubs have a built-in filtering system, it’s logical to ask why the system isn’t filtering out these impurities?

Almost all filters in the tubs have a pore size of around 5-10 microns in diameter. Any particulate matter larger than this is filtered and cleaned out automatically by the filtration system. Particles smaller than this, however, can’t be stopped and are free to flow through the filter. These are in the 3–4-micron range and form a colloid when it comes in contact with the water, which makes it cloudy.

Most hot tubs also have a passthrough water filling feature in which the water being filled bypasses the filter altogether and directly fills up the hot tub. These are intentional design elements to ensure that the tub can be filled, even when the filter is blocked or there is an issue with that circuit.

So, not 100% of the water filling the tub goes through the filtration system and contains elements that can contaminate the hot tub and make the water cloudy. For example, if you’re filling the tub with hard water, it’s bypassing the filter.

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Why Should I Periodically Clean My Hot Tub?

A cloudy hot tub not only looks unpleasant but might contain organic matter. This matter can act as a breeding ground for microbes and can lead to you feeling slimy after you get out of the hot tub. More significantly, it may also cause infections and diseases. The most commonly associated disease with a dirty hot tub is hot tub folliculitis.

Hot tub folliculitis is a common infection of the hair follicles on the skin from a bacterium called Pseudomonas aeruginosa. This bacterium is commonly found in hot and moist areas. The organism can spread by contact and shared use of articles such as combs, shaving razors, etc. As a result, periodic cleaning of the hot tub is important.

How Do I Make the Water in My Hot Tub Clear Again?

After finding yourself in a situation where you ask, why is my hot tub cloudy? The next logical question is how do I make the water in my hot tub clear again? Here are some ways you can clean and clear up your hot tub water (and we’ll cover each in detail below):

• Emptying and refilling the hot tub
• Testing the water source
• Shock treatment
• Ultrasonic treatment
• Filtering
• Clarifier

Emptying and Refilling the Hot Tub

If the water in your hot tub is cloudy, the easiest solution might be to simply empty and refill the tub. If doing this option, it could be helpful to also clean out the spa plumbing system too.

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Regardless of using a plumbing cleaner, just emptying and refilling the hot tub will clear out any debris or organic matter that has collected in the water and also give you a chance to clean the tub itself. Make sure to use fresh, clean water when refilling the tub and to follow the instructions on how to properly sanitize and maintain your hot tub.

However, if this doesn’t address the reason the water is becoming cloudy, the water may become cloudy again soon after the change.

Testing the Water Source

Testing the water source is also an important step in making sure the water remains clear in the long term. Make sure that the water filling the hot tub is within the normal range of chemical properties of soft water, such as:

• pH: 7.4-7.6 (slightly alkaline)
• Total alkalinity: 100-150 ppm
• Soft water
• Sanitizer: Chlorine 3-5ppm/ Bromine 4-6 ppm

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Having low sanitizer levels in the water can lead to the water being cloudy. There might be an overwhelming amount of organic matter in the water and not enough sanitizer to neutralize it.

If you’re using well water or another untreated source for your hot tub, it’s important to test the water to ensure that it doesn’t contain any impurities that might be causing the water to become cloudy.

The most common contaminants in well water are iron, manganese, and hydrogen sulfide. All of these can cause the water to become murky and cloudy.

Shock Treatment

Shock treatment is the process of adding a large amount of chlorine or other sanitizers to the hot tub in order to kill any bacteria or algae that may be present in the water. This will clear up the water and make it look more like its usual self. However, if the root cause of the cloudiness is still present, then the cloudiness will return.

There are a variety of chemicals that achieve this function:

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• Non-chlorine shock (most preferred): These are usually ozone-based treatments for cloudy water. Add 20 grams per 1000 liters of water.
• Chlorine Granules (bleach powder): These work on the bleaching effect of hypochlorous acid. Increase your chlorine level to 20ppm, and let the excess circulate away by leaving the tub’s cover off.

Ultrasonic Treatment

Ultrasonic treatment is a process where high-frequency sound waves are used to break up any organic material in the water.

This can be an effective way to clear up the water and address the root cause of the problem. However, it’s not always possible to use this method and it can be expensive.

Filtering

The filters in the hot tub are often overlooked as culprits. These filters usually have a mesh with a pore size of 5-10 microns. All particles above this size are strained by the filter. So, the filter requires regular cleaning to prevent it from getting blocked or worse, breached.

The filter needs to be taken out and thoroughly rinsed and cleaned with filter cleaning solutions to eliminate oils and grease, at least every two weeks. Hot tub filters need to be replaced every 6-8 months to maintain acceptable water quality.

Clarifier

If the water is murky, but not cloudy, a clarifier may be the solution you’re looking for. Clarifiers work by coalescing all the suspended particles in the water into larger clumps.

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This makes them more visible and easier to remove from the water. The downside to using a clarifier is that it can also make any algae present in the water more visible, which can look like cloudiness.

An example of a popular clarifier is potash alum. It is a brown clump, that, when dissolved in water, discharges many negative ions. These ions merge with the positive colloidal ions, creating an unstable suspension, which leads to the sedimentation of these particles on agitation, leading to crystal clear bathwater. 

After this treatment, you must take special care to clean out the extra debris accumulated in the filters to ensure proper functioning.

Using a clarifier on a regular basis will help keep your hot tub’s water looking clear without having to resort to more drastic measures.

Frequently Asked Questions

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Final Thoughts on the Question: Why is My Hot Tub Cloudy?

Many hot tub owners at one point or another have asked the question, why is my hot tub cloudy? Although there are a variety of ways to treat cloudy water, it’s important to identify and address the root cause of the problem.

If you’re tried the suggestions above and you’re not sure what’s causing the water to be cloudy, it’s best to consult a professional. They will be able to help you find the right solution for your specific situation.

In most cases, using a shock treatment and/or a clarifier on a regular basis should keep your hot tub’s water looking clear, beautiful, and sparkling all year long!