Why is there foam in my spa?

Have you ever looked out at sea and noticed froth or foam? It’s essentially the same as the foam that accrues in a spa, except it’s a different chemical composition.

Foam build-up in your spa happens now and again but is easy to eradicate. It’s not harmful but a build-up that happens. Even if you are very vigilant at cleaning and keep your spa’s water balanced, you will inevitably end up with foam at some stage.

If you’re struggling with cloudy water, click here for how to treat it! 

How does the foam form?

The foam in your hot tub happens because of surfactants that are very sticky molecules. Scientifically speaking, they are compounds that decrease the surface tension of liquids.

Surfactants, water and air are the natural ingredients to create foam. Activate the jets on your spa and the water is agitated – and you’ll initiate froth! This foam might be okay in a bath, but it’s less suited to a spa.

The foam usually occurs after your spa has had heaps of usage and you’ve neglected its maintenance.

What are surfactants?

The more surfactants in your spa, the more likely foam will build. Typical ones are:


These are probably the main culprit. Sunscreen, shampoo, conditioner, gel and deodorant can create a build-up. If you’ve got long hair, why not tie it up?

Click here for how you can protect your water from lotions!


How many of you have enjoyed a drink in your spa? Did just a teeny bit spill out? Alcoholic and sugary drinks are one of the main culprits to create foam.


Leftover detergent in a fabric will also mess with the chemical balance in your water. Wash your swimwear but don’t overload the detergents. It might be a good idea to rinse it with water beforehand.


Dead skin cells cover your body along with sweat oil and soap residue! If you don’t shower before you get in the pool, these dirty particles will get into the water. Wash down quickly before you enter your spa because all of these can throw the balance of your spa water off-kilter.

Eradicating Foam

The good news is that it’s simple to sort the problem out yourself. The first step is to check your water and investigate alkalinity levels, pH and calcium hardness. Your alkalinity level should be around 80-120 ppm. Your pH level shouldn’t be higher than 7.6.

Calcium hardness should be around 150- 400ppm. You may want to add an anti-foam chemical to help eliminate the problem. There are plenty available on the market.

If the foaming persists after 48 hours, then it’s taking everything back to a basic level. Drain, clean and rinse your tub and start from scratch – to eliminate all impurities. Once refilled, add the necessary chemicals and allow 24 hours before you start using your spa again.

Want to unwind and relax in a spa? Then why not invest in one from Barrier Reef Pools Perth. We have different spa shapes available in nine different colours!

Click here for a complete guide to owning your own spa!

Why not come to one of our three display centres around Perth and choose the one for you and let the power of the jets and the soothing bubbles massage your cares away? Reach out to us today!

Request A Free Quote Today​

We invite you to visit our display centres or contact us today for a free quote and site appraisal. Let Barrier Reef Pools WA and its skilled, experienced and friendly sales staff work with you in selecting the very best design to meet your special needs.

View Our Brochure


Visit A Barrier Reef Pools Display Centre​ Today​

With three display centres around Perth, there is always someone close by to answer any questions you have on our fibreglass pools and to show you our extensive range of pools.

Joondalup Display Centre
O'Connor Display Centre
Mandurah Display Centre
Share This Page: