If you’ve got a hot tub, then you’ll know one of the worst things that can happen is for the water to become discoloured. Not only is it unpleasant to look at, and totally ruins the enjoyment of your spa, but discoloured water could also indicate the presence of nasty algae and bacteria that could irritate your skin.

So, if the water in your hot tub has turned from clear and fresh to a nasty colour, in this article we’ll explain why it’s happened and how you can fix the problem.

Why does hot tub water become discoloured?

The first thing to discuss is why exactly it is that water in your spa can change colour. There are two common colours that hot tub water will turn, and that’s green or, less often, yellow. Spa water that’s turned either green or yellow does so because of the presence of algae – so this is the issue that you need to solve.

Hot tub water turning other colours is possible but usually indicates some kind of uncommon contaminant – check out our other guides on how to clean your hot tub to address any of these issues.

How does algae get into your hot tub?

Okay, so there’s definitely algae in your hot tub water – how does this happen? As with any other bodies of water, algae mostly grows in the sun, so it will generally only affect people with uncovered hot tubs. If your spa is left uncovered for long periods of time in the sun, algae will often bloom rapidly and can seriously discolour the water.

Other common ways for algae to get into a hot tub include being carried in from other bodies of water, so it’s important to wash any accessories or swimwear before entering your hot tub, especially if you’ve recently been in natural bodies of water.

Additionally, the presence of algae in your hot tub likely also indicates that something’s not quite right with the way you’re cleaning or sanitising it. You’re possibly either not adding enough sanitiser, or not adding it frequently enough. Or, the hot tub’s filters are dirty or not functioning properly.

How to get rid of hot tub algae and fix discoloured water?

If you’ve algae in your hot tub, one of the biggest questions you’ll have is how to quickly get rid of it and fix the issue. Luckily, you can do just that with a deep clean of your hot tub. Just follow these quick tips and check out our blog post on cleaning your hot tub for even more info:

  • Drain the hot tub
  • Carry out a full deep clean, ensuring you clean every surface
  • Clean the filters (or replace them if needed)
  • Clean the hot tub cover (or install one, if you don’t have one)
  • Refill the hot tub
  • Shock and balance the water as normal.

It’s possible, if you had a particularly nasty algae problem, that it’ll come back even after you’ve been through this process once. Unfortunately, this can happen – algae is very persistent. If it does, just give your hot tub another deep clean. Eventually, you’ll be able to shift all the algae and get your hot tub back to a nice clean state.

How to prevent algae in your hot tub?

Another common question is how to prevent hot tub algae from blooming in the first place. Here are our top tips:

  • Make sure you sanitise your hot tub properly and test the water to verify this
  • Check the filters and ensure you clean and replace them on a regular basis
  • Wash all accessories and swimsuits before they go in your spa, especially if you’ve been in a lake or other pool
  • Cover the hot tub with a high-quality cover whenever you’re not using it

If you need assistance with an algae problem in your hot tub, speak to BMS Spas. Our hot tub maintenance and cleaning programs will help you combat any persistent algae issue, and our spa experts can offer you friendly advice on how to ensure your hot tub stays in the best possible condition.