My hot tub water is green – what do I do?

My Hot Tub Water Is Green – What Do I Do?

Answer: Over the next few weeks the SpaChem team will be discussing and supporting hot tub owners with troubleshooting guides with what to do when you lift off the cover and find that the water is far from crystal clear. It doesn’t matter which make, model, or size of hot tub you own; the general rule of water management is the same for all.

Starting with one of the more common colours; green.


Is your hot tub water green?

If your hot tub water is green and you’ve tried the usual to try and get rid of the green water, we’re here to help. We’re here to share some helpful advice on how to keep your hot tub clean. So, with that said, let’s look at the causes of green hot tub water and how you can avoid this from happening.

What’s causing my hot tub water to be green?

Green hot tub water is commonly caused by a simple, non-flowering aquatic plant. Ok, that’s just a nicer way of saying that it’s highly probable that you have algae in your water after all, algae love to grow under the cover of your hot tub in the dark yet warm water environment.

One of the simplest methods to test if it is algae causing this problem is to touch the inside of your hot tub walls, if it feels slightly slimy to the touch, then the chances are its algae. The likelihood is that this has happened due to either insufficient sanitiser levels (Chlorine or Bromine) in your hot tub or your filter is not performing at its best.

Minerals such as copper, iron and manganese can also make the water turn green. These minerals could be from corrosion of equipment, from copper pipes or just minerals from your household water.

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Is green hot tub water safe?

If you’ve opened your hot tub cover to discover green spa water or a green tint to the water, it’s not advisable to use it. However, this can be easily fixed and isn’t a huge issue. If the hot tub water has been green for over 24 hours you will need to conduct a deep and thorough clean.

You should firstly have a deep clean of your hot tub. This includes draining the hot tub and giving it a thorough clean.

You will need to use your garden hose to clear away the green tinge to the hot tub and remove any algae growth. Once the hot tub has been treated for the algae growth and green water, you will then be able to refill the hot tub with the appropriate treatment.

How to solve it.

Test the pH and alkalinity of your hot tub water and try a Hot Tub Shock / Non-Chlorine Oxy Shock. After filtering out the dead algae we would recommend that you look to clean your filter to remove any loitering algae. For more information on the products available and how to conduct a shock treatment, visit

If the above has not rectified the problem and 24 hours later, your water is far from crystal clear, then it’s time to drain your water, thoroughly wipe all of the internal surfaces of your hot tub (to remove any remaining algae), replace your filter and refill with fresh water, not forgetting to balance your waters Total Alkalinity, then pH which will ensure you are giving your sanitiser the best water environment to work at its best.

Other considerations.

There are other causes of green water such as the presence of minerals (copper, manganese, and iron is the main culprits) from the pipes that fill your hot tub, or even present in your household water and don’t forget the no-go rules around fake tan. The chemicals in your hot tub will react with the fake tan and result in some interesting shades of brown and green on the sides of your hot tub and in the water!

Why choose SpaChem for hot tub cleaners and chemicals?

We have been providing chemicals, cleaners and filters for hot tubs and swimming pools for many years now, so regardless of your needs and requirements we’re more than confident in saying that we can help.

No matter if you’re in need of hot tub maintenance products or something for a chemical imbalance, we’re here for you. Please be sure to browse through our range of products for hot tubs and swimming pools.

For more information about us or any of our hot tub products, please waste no time and be sure to give our team a call today.

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Tips to avoid your hot tub water going green

  • Always keep your hot tub covered when not in use
  • Make sure you add enough sanitiser for your hot tub’s volume
  • Check the filtration system
  • Clean your hot tub filters regularly
  • Always ensure you have clean hot tub water
  • Refill your hot tub with clean water regularly
  • Wash your swimsuits or any accessories you wear in the hot tub before using

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Contact SpaChem for green hot tub water treatment

If you’re in need of further advice on how to take care of your hot tub water, please waste no time and be sure to get in touch with us today. Nothing is off-limits for us, so no matter your needs regarding hot tub cleaning and chemicals, please waste no time and be sure to choose us. From treatment for green water to hot tub care advice, we’re always happy to help.