How To Fix Cloudy Hot Tub Water

Cloudy hot tub water is one of the most common issues which all hot tub owners will face at some point in their lifetime. But don't worry, we’ve created this guide to help you turn your hot tub’s water from a cloudy haze to crystal clear.

Why Is My Hot Tub Water Cloudy?

First of all, it’s important to understand why your hot tub’s water has turned cloudy. There are a variety of different substances that can cause this, resulting in lots of tiny particles floating in the water to give it its cloudy appearance. These particles can come from a variety of different substances, including:

- Environmental matter: dust, pollen, seeds, and small airborne particles will fall into your hot tub.

- Organic debris: skin cells and natural body oils will wash off into the water.

- Cosmetics like lotions and moisturisers: these will wash off the bather, particularly when the water is warm (just like in a bath or shower).

- Algae growth: without effective water treatment, algae and other bacteria will begin to form.

Don’t Blame Your Hot Tub’s Filter

Before you go ahead and start feeling animosity towards your hot tub’s filter, it is important to remember that the majority of the particles that form in a hot tub are too small to be collected by a filter. Most filters will remove particles down to about 5 to 10 microns - to give you an idea, a red blood cell is about 5 microns in diameter or 0.005 millimeters.

The pump has also been designed to not force all water flow through the filter. This is because if the filter gets severely blocked it could cause damage to internal components of the pump.

It is these reasons that mean that although a filter does filter a lot of debris, it can never capture everything – this is where chemicals come in.

Make Your Hot Tub Water Clear Again

Although it might look like a challenge, returning your hot tub’s water back to its original clarity isn’t as difficult as you might think. Follow these steps to fix cloudy hot tub water using chemicals or empty your hot tub and refill with fresh water.

Shock Dosing Your Hot Tub

Just like how you would have ‘shocked’ your hot tub when you first set it up, a shock dose will help to fend off any bacteria or algae by oxidising the water, creating an environment in which all the bad stuff can’t thrive in.

In order to shock dose you need to:
1. Test your hot tub’s chemical levels with a Dip Test Strip
2. Shock dose your hot tub with Chlorine Granules. This shock dose will be dependent on your hot tub’s capacity. We recommend 20g of chlorine for 1000 litres (E.g. The Miami AirJet would require 16g of chlorine or 3 teaspoons).
3. After you’ve carried out the shock dose you should wait for a minimum of 24 hours before testing your water with the dip test strips
4. You can start bathing again once the water’s chlorine levels have returned to 3-5ppm

After you have shock dosed you should notice a considerable improvement in the water quality.

For more information, read our handy shock dosing guide and consider our Shock Dose Pack, which contains everything you need to shock dose your hot tub.

Use Algaecide And Clarifier to Help With Cloudy Water

If the water is still cloudy following a shock dose, using a combination of Algaecide and Clarifier can help to collect up the remaining residue.

Rather than just helping to discourage algae growth, Algaecide is a chemical treatment designed to kill and prevent algae growth (please follow product instructions). Following an algaecide treatment, we recommend using Clarifier. Clarifier works by coagulating the small particles (the dead algae and other particles). These particles are then large enough to be captured by the filter and therefore remove any cloudiness from the water (please follow instructions). Once the filters have had a chance to work their magic, make sure you clean them thoroughly to ensure they remain effective.

How To Prevent Cloudy Hot Tub Water

There are a number of simple things you can do to help prevent or at least reduce the likelihood of getting cloudy hot tub water:

- Make sure water chemical levels are correct through regular dip tests
- Clean filters regularly
- Rinse swim costumes, bikinis, or shorts in warm water rather than detergent
- Shower before jumping in your hot tub to help remove dead skin and other moisturisers

Cloudy Hot Tub Water: Summary

Cloudy hot tub water is a common problem for many users, but this can be easily fixed by following some simple steps:
- Drain your hot tub if the water is over 4 to 5 weeks old
- Carry out a Shock dose treatment if the water is less than 4 weeks old
- Use algaecide and clarifier to remove any remaining debris
- Clean your hot tub’s filter


For any more help and advice with chemicals and water troubleshooting, please visit our Chemical Guide.