Are you struggling with keeping your hot tub water clear from cloudiness? We have some tips and advice to help you get your hot tub sparkling again.
Hot tub water can go cloudy for a number of reasons;

  1. Incorrect water balance
  2. Poor or insufficient filtration
  3. Low levels of sanitiser
  4. A build up of bather waste

Incorrect Water Balance – THE SOLUTION:

Total Alkalinity is a measurement of the waters ability to resist pH change. If the total Alkalinity is low then the pH can fluctuate making it difficult to control and maintain at ideal level. If the total alkalinity is high than the pH can be difficult to change and will keep rising. A high total alkalinity can also lead to the formation of a bicarbonate scale on hot tub surfaces, within pipework and support equipment.

If the total alkalinity of your hot tub water is below 80mg/l it should be increased using Alkalinity Increaser. If the total alkalinity of your hot tub water is above 150mg/l then pH Minus can be used to lower it.

The ideal pH for hot tubs is between 7.2 and 7.6. Test your hot tub water and if the pH reading is above 7.6 this can be a contribution towards cloudy water. To lower it use the following chemical, pH Reducer.


  • Pre dissolve the pH Reducer in a clean plastic container at a maximum rate of 10g of product per 0.2 gallons (1lts) of clean warm water. Stir well to ensure product is fully dissolved. Carefully add the resulting solution to the hot tub whilst the pumps are turned on, preferably near to the water inlets to aid distribution
  • After a minimum of 30 minutes recheck the pH level and if necessary repeat the treatment until the ideal pH is established

Poor or Insufficient Filtration – THE SOLUTION:

Filters play a huge part in keeping your hot tub clean and safe to use. If your filters are clogged with grease and oil this can play a part in your cloudy water problem. Use filter cleaner chemicals as part of your regular cleaning routine for your hot tub cartridges. Filter cleaner chemicals will remove grease and oil from filter cartridges so should be used on a fortnightly basis or more frequently if your hot tub sees heavy use.



  • Remove filter(s) from filter compartment and hose down with fresh water to remove loose matter
  • Thoroughly spray filter(s) with Instant Filter Cleaner taking care to penetrate veins with product
  • Leave the filter(s) to stand for 15 minutes, then hose down thoroughly with fresh water


  • Add Immerse into a clean plastic bucket containing clean water and stir well
  • Hose the cartridge to remove any loose debris, and then soak it in the cleaning solution for at least 8 hours
  • After soaking the cartridge rinse it thoroughly with fresh water and if possible allow it to dry before returning it to the hot tub


  • Remove cartridge from hot tub and remove any loose debris
  • Fill a clean plastic bucket, large enough to completely immerse the cartridge, with clean water
  • Add 1 litre of Cartridge Cleaner for every 20 litres of water in the bucket
  • Carefully immerse the cartridge in the solution and allow it to soak overnight or for at least 8 hours
  • Remove cartridge from the solution and rinse thoroughly with fresh water

*FOR BEST RESULTS: Make sure your filter(s) are completely dry before putting them back into your hot tub. This will enable the material fibres to form together and prevent particles from getting through. The regular chemical cleaning of filter cartridges will help promote sparkling water that is easier to maintain.


Keeping your sanitisers at the correct level will help to prevent cloudy water.

Chlorine is a common chemical used to achieve satisfactory bacteriological and chemical purity in spas. Providing that your water is balanced, chlorine levels of between 3.0 to 5.0mg/l are sufficient to maintain healthy, clean water.

Bromine is similar to chlorine in its effectiveness as a sanitiser but there are some important differences that make it an ideal product for using in a hot tub:

  • Bromine tablets should be dosed into a spa via a floating dispenser
  • Bromine retains better levels of efficiency over a wider pH band, which makes it ideal for spas as the pH can fluctuate a fair amount

A Build Up of Bather Waste – THE SOLUTION:

If possible it is always a good idea to encourage hot tub users to shower, with their costumes on, before getting into the hot tub as this will not only help in removing detergents but will also remove cosmetics and lotions from the body.


Spa Sparkle will quickly restore water clarity, but before using it you should ensure that:

  • The water is correctly balanced
  • The circulation and filtration system are operating correctly and the filter is clean
  • The sanitiser level if being maintained within the ideal range

Once you are satisfied that the above conditions have been met then Spa Sparkle can help speed up the clarifying process.

Spa Sparkle is added directly to the hot tub water with the pumps running. Once applied it collects small particles and binds them together making larger particles that are much easier for the filter to remove. Regular small doses of this product are all that is required to keep hot tub water looking crystal clear.

We hope that this information has helped you to regain your water clarity.
These are guidelines and it is a case of taking the time to maintain and keep on top of your chemicals.

Over time spa water can become ‘stale’ as it absorbs minerals, chemicals and other soluble materials that cause total dissolved solids (T.D.S) to increase. When the T.D.S level reaches 1,500mg/l it is time to drain that water out of the spa and refill it with fresh new water.

As a guide it is best to have your hot tub drained and refilled every 2-3 months.

For more information please give our office a call on 02392 471 073.