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  • Writer's pictureAqua Warehouse

What Causes Cloudy Hot Tub Water and How to Fix It

Updated: Jan 4, 2023

One of the most common questions our hot tub accessories team is asked, is how do I fix cloudy hot tub water? Cloudy hot tub water is a common issue for spa owners. With regular use, hot tub water can quickly turn from being crystal clear to a hazy grey very quickly.

What Does Cloudy Hot Tub Water Mean?

When hot tubs take on the appearance of a milky pool or have excessive foam, this is known as cloudy hot tub water.

Why is my hot tub water cloudy?

Because the water has lost its clarity. Instead of being crystal clear and inviting, it has become dull and hazy. This is usually caused by suspended particles in the water that are too small to touch or get picked up by your filters.

Is it Safe to Use a Hot Tub With Cloudy Water?

Are you wondering whether it is safe to use a spa or hot tub when the tub water is cloudy? The short and simple answer is no. For safety reasons, the water in your hot tub should be clean and sanitary. Cloudy spa water indicates something is wrong. It could be excess bacteria or a chemical imbalance. You should rectify the situation before using the spa or hot tub again.

What Causes Cloudy Hot Tub Water?

Several things can cause cloudy spa water. Here is a list of the most common causes of cloudy hot tub water:

  • Heavy use of the hot tub: A common cause of cloudy hot tub water is heavy usage. The more you use your hot tub, the more often you have to deep clean the hot tub water. Especially if you hold a hot tub party.

  • Pollutants in the air: Many pollutants and organic debris such as pollen, dust, and insects float around in the air. Eventually, these are going to find their way into your hot tub water.

  • Bacteria and algae: The warm water in your hot tub is a perfect breeding ground for algae and bacteria. Not only can bacteria growth cause cloudy or unclear water. Bacterial growth can also cause severe skin irritations.

  • Chemical imbalance: To ensure the clarity of your hot tub water, you must maintain the correct water balance. Do this by using the right hot tub chemicals to balance the water chemistry. Keeping an ideal sanitizer level is a cornerstone of basic hot tub chemistry and will help maintain water that is safe, clean and clear. Unbalanced water can result in staining, scale build up and green, foamy, or cloudy water.

  • Poor functioning filtration system: If your hot tub filtering system is old, poorly fitted, not working correctly or is overused, the filters will not function efficiently and remove particles. An ineffective hot tub filter will eventually cause cloudy water.

  • Body care skin products: When you use a hot tub, substances on your body will end up in the water. Products such as body oils, makeup, hair conditioners, and lotions affect the water quality. Dead skin cells can also be a problem and can lead to foaming in the water.

  • Metals in the water: If you fill your hot tub from your house, the metals in the water could be the main reason to turn your hot tub water cloudy.

  • Poor water care: A poor maintenance schedule could lead to cloudy water. Make sure you check the hot tub water regularly, drain and refill it every 60-90 days, and use the right hot tub water chemicals. Using incorrect or cheap chemicals can also lead to foam forming in the water.

  • Air in the system: Tiny bubbles or small air particles can make spa water look cloudy or foamy on the surface.

  • Poor circulation: Allowing your hot tub water to sit for long periods could lead to it becoming cloudy.

How Do You Clear Up Cloudy Water in The Hot Tub?

There are 5 most commonly used methods to clear up hot tub water. Note that sometimes you will have to try a few of them until your reach the desired result.

1. Check water pH and Alkalinity levels

You can test your water using a test strip and drop-style kits. The core levels should be as follows:

  • pH level: 7.4 - 7.6

  • Total alkalinity: 100 - 150 ppm

  • Sanitizer levels: Chlorine 3-5 ppm/Bromine 4-6pp

You could also take a water sample to a hot tub, pool and spa store so that they can test your water for you with professional equipment. After testing, you can adjust the chemical levels accordingly.

2. Shock treatment

If it is minerals making your water cloudy, you may need to shock your hot tub. If your hot tub uses a chlorine sanitizer or other minerals, you should use powdered chlorine or a non-chlorine shock.

If your hot tub uses bromine sanitizers, try a non-chlorine shock or powdered bromine. such as the YourSpa Non-Chlorine Shock Treatment. This product will also help those on bromine to activate the bromine and help it work more effectively. Non chlorine shock treatments are usually a preferred treatment by hot tub.

When you add sanitizer to shock hot tub water, it eliminates organic matter by turning it into a gas. . To prevent your hot tub water from going cloudy, treat it with 30g (1 capful) of granular sanitizer to ensure the level rises back to the safe range. Add sanitizer as required based on your test strip results. On average most people add sanitizer 2-3 times per week. Remember to shut off the air valves when adding chemicals.

3. Check and clean the filters

Filters can also affect the cloudiness of your water. Your hot tub filter requires regular cleaning, a blocked filters mean that they aren’t doing their job properly, so make sure filters are rinsed regularly and treating with a filter cleaner periodically to remove oils and greases.

Substances such as dead algae can build up in your hot tub filters and upset the water clarity. Check them weekly, rinse them regularly, use a filter cleaner to wash them at least once a month. Fit a new filter every 6-12 months.

4. Use algaecide or water clarifier

A clarifier coagulates and brings together all the minute particles your hot tub filter fails to trap. The filter can then trap the now larger particles and remove them. Take care not to use too much because it could make the problem worse. An algaecide kills and prevents algae growth, and ideally, you should use it before the clarifier.

5. If nothing else helps, drain and refill the hot tub

As a last resort, if none of the above resolves the problem, the best thing to do is empty your hot tub or spa, clean it, and then refill it with fresh water.

How Can I Prevent Cloudy Water in My Hot Tub?

Prevention is the best way to stop cloudy swimming pool/hot tub water from occurring. Ideally, you want to make sure hot tubs contains no contaminants.

Always shower before jumping in the hot tub. This means rinsing yourself off in clean water and not using any soap.

If users wear swimming costumes, this can dirty the water. To avoid this, rinse them in warm water and avoid using detergents.

Here are some simple steps to eradicate cloudy water:

  1. Use clean and filtered water: If you use clean water that has been carefully filtered, this is the first thing you should do. Installing a hose pre-filter will help to keep the water clean when you fill your hot tub.

  2. Check for dirty filters and clean them regularly: A clean filter keeps the hot tub's water clear and clean by preventing scale or any slimy substance from building up. Always follow a regular maintenance schedule that includes checking the filter, rinsing the filter every week, cleaning the water filter every month, and replacing it whenever necessary. Most filters should last around twelve months before you need to replace them. But, if you notice any tears or the filter pleats are stuck together, it makes sense to replace the filter straight away. Otherwise, it will be ineffective in trapping particles and contaminants.

  3. Make sure the chemical balance of your hot tub is right: You should check the hot tub chemical levels regularly. You must monitor alkalinity, pH, sanitizer and calcium levels. If necessary, adjust them. You can use chemicals such as alkalinity or pH decreasers. By being proactive and balancing your hot tub, you reduce the risk of cloudy water.

  4. Follow a regular hot tub maintenance schedule: Prevention of cloudy hot tub water is often a case of routine maintenance and cleaning.

  5. Drain the hot tub and replace the hot tub water: Every three months, drain the water from the hot tub, clean it, and then refill it.

  6. Hot tub cover: Using a hot tub cover will prevent airborne debris, particles and other contaminants from falling into the water.


Cloudy water in a hot tub is one of the most common issues faced by owners. So let it get you down! It can be caused by several things, but the first step to a solution is to pinpoint the root of the problem and then try the fixes listed above.

If you face this issue, avoid using the hot tub until you fix the milky or cloudy problem and achieve crystal clear water again.


How long does it take for cloudy hot tubs to clear up?

It really depends on the remedy you use to clear the hot tub water. However, on average, you can expect it to take around 24 hours for the water to be restored to a clear state after cleaning or shocking.

How long does it take for cloudy water to clear after shocking?

Can too much chlorine cause cloudy water?

Will low or high pH cause cloudy water?




Jess Court

I'm Aqua Warehouse Groups Marketing Officer - overseeing all things news worthy in the hot tub industry, with tips and tricks that are bound to make a splash.

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