What to Do If Your Hot Tub Water is Cloudy, Foamy or Green?

Have you noticed your hot tub or swim spa water looking a bit strange? Don't worry, we’re here to help! Read on to learn how to keep your water in tip-top condition so you can relax in a clean, healthy environment.

What makes hot tub water green?

Green hot tub water can be caused by algae, which is usually a sign of an insufficient sanitisation level (chlorine or bromine) in your tub.

Minerals such as iron, copper and manganese can also turn the water green. These could be from copper pipes, corrosion of equipment or even minerals in your household water. Tanning products are removed from the skin by the chemicals in the hot tub, which can turn the shell, pipework, and internal systems brown or green.

Hot tub water care is crucial in ensuring that water stays clear, sanitary, and ready to use. Pay attention to any problems and continue maintaining the water to eliminate the risk of bacteria growth, which causes murky water.

How to clear green water in a hot tub

If the water’s been green for less than 24 hours, you may be able to revive it:

  • While your hot tub is not in use, remove the cover and any pillows.
  • Add 60g of sanitiser (chlorine or bromine) per 1,500l of water and turn the jets on for one cycle.
  • If this has worked, you’ll see the water begin to clear within 12 hours. Once it’s clear and the sanitiser has dropped to a safe level, you can use the hot tub again.

If the water’s been green for over 24 hours or the above hasn’t worked, the best way to clear it from your tub is:

Clean water running through a waterfall a hot tub
  • Drain the water, clean the tub thoroughly and refill with fresh new water.
  • Clean the filters and wipe down the interior to remove any remaining dirt.
  • Add your sanitiser and balance the pH once the hot tub has reached the correct temperature (usually around 38°C). Getting the balance right is crucial, so don’t overdo it with chemicals, as too much chlorine can damage the hot tub and irritate your skin.

For more information, check out our guide on hot tub chemicals.

Why does hot tub water become cloudy?

The main reason hot tub water becomes cloudy is that it’s old and needs replacing. Even with chemicals, your hot tub water should be emptied and refilled with fresh water every three to four months. If this isn’t the case, there are a few more things you should consider:

Sanitiser levels

If your chlorine or bromine levels are low, it can lead to poorly sanitised, cloudy water. Try adding a sprinkle of extra sanitiser.

pH levels

Check your water’s pH levels to see if they’re off balance. If the water becomes more alkaline, limescale can accumulate and increase the water’s cloudiness.

Hot tub filters

Hot tub filters remove dirt from the water, but they can become clogged and unable to filter it if they’ve not been cleaned or changed for a while. This leaves behind dirty, cloudy water. Thankfully, this is easy to keep on top of if you follow some simple steps, learn how to clean a hot tub filter.

External substances

Most cases of cloudy water originate from substances that you unknowingly bring into the hot tub. This can be deodorant, moisturiser, conditioner, or debris from your feet as you enter the tub. Washing powder residue can also play a big part in causing cloudy water, so consider rinsing your swimwear in clean water before entering a hot tub. An outdoor shower makes this as easy as possible. 

How to treat cloudy hot tub water

Hot tub water testing

Firstly, test the chemical levels in your water to ensure they’re correct. It’s easy to test the water with our hot tub test strips. A hot tub shocking treatment will kill any bacteria and reactive sanitisers. Make sure you deep clean or replace the hot tub filter.

Get advice on how to shock your hot tub in our guide. If the above doesn’t work, drain and clean your hot tub before filling it with fresh water.

What causes hot tub foam?

Foamy hot tub water is usually caused by everyday contaminants like:

Hair products

Woman in hot tub with swim cap

Your hair contains residue from products like shampoo, conditioner, gel, hair spray and mousse. These are transferred from your hair to the water upon contact. You don't need to get out your swimming cap just yet... we prefer to tie our hair up to reduce the amount of residue.

Deodorant, body moisturiser and perfume

Cosmetics like make-up and moisturisers can cause foaming in a hot tub, a quick shower before you soak will help minimise foam.

Washing powder

One of the most common errors people make is to wash swimwear in a washing machine. We recommend handwashing your swimwear to avoid unwanted detergent residue entering the hot tub.

Cheap or excessive amounts of chemicals

Cheap hot tub chemicals are often packed with filler that dilutes the chemicals, reducing their effectiveness and creating foam.

Drink spillages

Be careful with drinks in the hot tub, as spilling drinks can lead to foaming.

High TDS (total dissolved solids)

Total dissolved solids are minerals, salts, and metals dissolved in water. When the level of TDS in your hot tub becomes too high, the water will ‘die’, and the chemical balance will be challenging to maintain, which causes the foam to form.

How to remove foam from hot tub water


Start by testing the water for a chemical imbalance, beginning with your chlorine/bromine and pH levels.

Try using your usual chemicals to restore the balance. If that doesn’t work, you could use a no foam product that clings to the pollutants in the water and sinks them to the bottom so they can be removed by the filter.

If it’s a TDS related issue, the only solution is to replace the hot tub water, which should be done every three to four months. You should also clean the filter weekly and replace it every 12 months.


How to prevent hot tub foam

Outdoor Shower

The easiest way to stop the hot tub water from becoming foamy is to shower before getting in. This will rinse off all cosmetics, perfumes, moisturisers, and tanning products. For minimal faff, consider an outdoor shower

Tie up long hair to prevent it from entering the water, and rinse swimwear under warm water to wash away any unwanted detergent residue. To prevent drink spillages in your hot tub, try a Spa Caddy Table. They’re designed to keep your drinks upright; however powerful your jets are.

We recommend that you read the guidelines provided for chemical usage with your hot tub make and model, and always check the grade of chemicals before purchasing from a trusted source. We sell chemicals that are formulated to an exceedingly high standard, you can browse through our range here.

Parting advice

Pay close attention to any abnormalities with your hot tub or swim spa water and keep it protected with a thermal cover when not in use. By committing to a regular maintenance routine, your hot tub will be ready to use at the drop of a hat.

If would like to book a service, you can contact us here.

Need more advice? Give us a call on 01482 212322 or email enquiries@outdoorlivinghottubs.co.uk and we’ll help you out. Or drop in and see us in our Hull or Leeds showrooms to see our hot tub chemical range for yourself. 

Not near one of our Yorkshire hot tub showrooms? No problem, if you’re looking for a new hot tub you can explore our virtual showroom or book a video call with our showroom team

Stay up to date with our latest products, hot tub guides and updates on Facebook or Instagram.

Older Post
Newer Post
Close (esc)


Use this popup to embed a mailing list sign up form. Alternatively use it as a simple call to action with a link to a product or a page.

Age verification

By clicking enter you are verifying that you are old enough to consume alcohol.

Shopping Basket

Your basket is currently empty.
Shop now