Skip to content
Chemical Solutions
Hot Tub 101
Hot Tub Maintenance

Why is my Hot Tub Water Cloudy and How to Fix it?

Is your hot tub water cloudy? Don’t worry! It’s a common problem and it is usually an easy fix.

To safely enjoy your hot tub, your water should be clear enough that you are able to see the bottom of the spa. When the water is cloudy, it’s a sign there is a problem. It is important to figure out why your water is cloudy and how to fix it.

What causes Cloudy Water?

Typically, cloudy water is blamed on an elevated pH level, an elevated alkalinity level, and a low level of sanitizer. Other reasons for cloudy water can include dirty filters, body oils and fluids, and old water.

Elevated Alkalinity and pH Levels
Alkalinity measures substances in your water like hydroxides, carbonates, and bicarbonates. When they are balanced (in appropriate amounts), these elements will keep your water from getting cloudy and bacteria from forming. When you test your hot tub water, the alkalinity levels should be between 80-120 parts per million.

Hot tub water should also have a neutral and stable pH level. This will ensure your hot tub remains safe to use. An elevated pH level can also create cloudy water, eye or skin irritation, tartar buildup and keep chlorine from functioning properly. The ideal pH level should be between 7.2 – 7.6.

Low level of Sanitizer
To keep bacteria from growing, chlorine or bromine are added to your water. When these sanitizer levels are too low, water can get cloudy.

These two sanitizers function the same, but the treatment differs.
  • Pricier than chlorine
  • Slightly more complicated to administer
  • Treatments last longer
  • Treatments require less chemicals than chlorine
  • Less expensive than bromine
  • Easier to administer
  • Treatments require more chemicals than bromine

Personal Hygiene Products
Anything you have on your body upon entering the hot tub can have an impact on your water. Products like body lotion, conditioner, and oils can cause issues, ranging from neutralizing the sanitizer to creating a cloudy and foamy water.

Rinsing or showering before getting into the hot tub might seem excessive but this may also help prevent issues with your water down the line.

Woman in hot tub

Filter Issues
Filters are an important component of your hot tub. The filter will help eliminate particles, such as dirt, debris, algae, etc. from circulating in your hot tub water. Essentially, any particle introduced to your water may cause an issue and lead to cloudy water.

If your filter is blocked or not installed properly, it will not function correctly and can contribute to cloudy water. The filter’s job is to catch any debris floating in the water and remove it, but while the filter does this, particles eventually accumulate and can lead to your filter getting blocked. If your filter is blocked, it cannot filter the water as efficiently, thus leading to cloudy water.

Anti-foaming Agent
You can use an anti-foaming agent when you notice foam forming on the surface of your water. Excessive use of this product, however, may also lead to cloudy or milky water.

How to clear the cloudy water in your hot tub?
Getting your hot tub water back to normal should not be too difficult. The first step is to ensure that your water is chemically balanced before anything else.

1. Balancing your chemicals
To keep your hot tub clean, there are 4 important elements to consider:

✔ The alkalinity level must be between 80 and 120

✔ The pH level must be between 7.2 and 7.6

✔ The sanitizer levels should be between 1.5 and 3 for chlorine and 3 and 5 for bromine

✔ The amount of organic matter in your water

Chemically, these elements are all related:

  • Odors and algae form when organic matter feeds bacteria in the water, which then makes the water turn green and cloudy
  • Sanitizers will prevent bacteria from growing
  • pH levels affect the sanitizer’s efficiency
  • Alkalinity levels determine the stability of the pH levels

To ensure all of these elements are properly controlled, 5 things are required:

✔ Test strips

✔ Alkalinity Booster

✔ pH adjuster (pH Up, pH Down)

✔ Sanitizer (bromine or chlorine)

✔ Shock Treatment

The Cover Guy offers multifunctional strip tests that allow you to test all chemical levels at once.

4-Way Test Strip results


  1. Dip the strip test in your hot tub water
  2. Compare the color of the strip to the color on the package
  3. Verify the alkalinity level, followed by the pH level and sanitizer
  4. If one of the above-mentioned elements is not balanced, add the appropriate chemical to adjust:

a. If multiple elements need adjusting, adjust one at a time
b. Add the first chemical, then wait several hours or overnight
c. Test again and add the next chemical (as required)
d. Repeat as needed

You need to balance the pH and alkalinity levels before adding any sanitizer or chlorine-free shock treatment.

When adding chemicals, ensure that your hot tub is running, the air valves are closed and the cover is off the hot tub completely. Remember to remove your hot tub cover for at least an hour.

2. Shock Treatment
An appropriate amount of sanitizer will help destroy any particles that may have accumulated causing the water to turn cloudy.

Once the chemicals in your hot tub have been balanced, add a chlorine-free shock treatment to your water. This treatment will help clear your water by oxidizing organic matter before it can feed any bacteria. It will also help get rid of any leftover sanitizing residue.

This should be done weekly or at least regularly, depending on how often your hot tub is used. Once your water is cloudy or giving off foul odors, consider doing a shock treatment. Also consider doing one if your spa hasn’t been used for a long period of time.

3. Rinse and clean Filters
The frequency of which you should clean your filters depends on how often you use your hot tub and the weather.

The filter should be rinsed regularly twice a week, or as needed.

The rule of thumb is to clean your filter once every two weeks with a filter cleaner that will allow you to get into each individual pleat and remove any built-up residue.

Pro Tip

Once a month

Remove your filter and let it soak in a filter cleaning solution unless you notice an abnormal accumulation of residue.

Once a year

Remove and replace the filter with a new one, regardless of use.

4. Use a hot tub chemical clarifier
If you have balanced the chemicals in your hot tub, you can use a chemical clarifier to remove the cloudy water altogether. A clarifier pulls together the dirt particles, which then allows the filter to completely remove these particles from the water.

5. Empty and refill your hot tub
If you still have issues getting your water clear, you can always empty your hot tub and refill it. With time, residue and particles accumulate and it may become more difficult to keep your water clean and clear.

You should consider emptying and refilling your hot tub every six months or so. When you refill your hot tub, ensure you have a Stain & Scale solution handy.

At first glance, cloudy water may seem like a difficult problem to solve, but most of the time, it is simple enough. Often, you will be able to pinpoint the cause easily, but other times, it may be a combination of elements that lead to cloudy hot tub water.

If you are still unable to resolve the issue after following the steps outlined above, consider using a hot tub clarifier. If this still doesn’t help, simply empty and refill your hot tub, which will ensure you have fresh and clean water.