Say goodbye to cloudy spa water forever

With the cooler weather already here, our spas will probably be seeing more action that they regularly do than during the summer. And if there’s one issue that keeps popping up in our support channels, Facebook, and even online forums is the problem of cloudy spa water. Not only is cloudy spa water an eyesore, but it can actually be dangerous depending on the cause! Today, we’re going to be looking at the specific causes of cloudy spa water and how they can actually be dangerous!

Algae Growth

Just like swimming pools, one of the most common causes of cloudy spa water is algae. Algae in itself isn’t dangerous per se, but it can cause reactions to anybody who is sensitive to them. Lucky for us, algae in spas, due to the smooth surface and the small volume of water can easily be taken care of by shocking it. After shocking the spa, that should take care of the cloudiness. The only thing to remember though is to check the sanitiser levels have gone down to safe levels (1ppm to 3ppm) before using the spa.


This problem is basically your algae growth taken to the next level and usually presents itself if the spa has sat idle for some time unused (especially over the summer). Biofilm is a slimy colony of bacteria that hides out of sight and can only be detected once slimy flakes start to cloud up your spa water. We don’t really really have to explain how a colony of bacteria can be dangerous right? For biofilm removal, lower the pH level of your spa water to around 7.2 or lower and then shock the water to at least 10ppm or higher to kill the colony. After that, use some Lo-chlor Pipe Klenz to melt away the remaining gunk from the pipes and to flush them out for good.

Non-Chlorine / Non-Bromine Sanitizer use

Although non-chlorine and non-bromine spa sanitisers are technically better for your spa and for the users, this can actually be the cause of many “unknown” spa cloudiness issues! This is one of the main reasons why biguanide sanitisers require very specific chemicals to pair with. They cause interactions with other “regular” pool and spa chemicals that can cause cloudiness and even some strange colors! So if you have a non-chlorine or non-bromine spa then you should go all-in and not mix and match chemicals!

Salt Water Chlorinator Issues

While salt water chlorinators are not a common thing to use with spas, with some creative plumbing work, your full sized chlorinators can actually be used with the spas. There’s also the option of using drop-in salt water chlorinators, but that’s something for another day. Using chlorinators can lead to a false sense of security when it comes to sanitising your spa. If you’re using a salt water chlorinator with your spa, always make sure that all the valves are turned to where they’re supposed to be and that salt levels are where they’re required for the chlorinator to work. The most common problem that causes cloudiness in spas that use salt water chlorinators is the salt levels going down from the constant water replacement (yes, a lot of salt and water goes out whenever someone steps out of the spa, volume-wise).

P.S. If you're thinking about converting your spa to a salt water spa, then we highly recommend our smallest sized chlorinator, the Water TechniX WTA15. It has more than enough muscle to keep your spa water chlorinated even through heavy usage!

Body Oils and Other Contaminants

Due to the small volume of water in spas, the water can easily cloud up from lotions and other cosmetics that get dumped into the spa whenever it is used. The high temperatures of the spa will also lead to more body oils being secreted and being deposited into the spa. Remember when they say that spas are good for detoxing? Well, the toxins (oils and other body fluids) need somewhere to go, and that’s into the spa water! Thankfully, the fix to this is quite simple, just shock the spa after heavy usage and that should prevent cloudy spa water.

It's also prudent to take a shower or rinse before taking a dip into the spa to minimize the introduction of these contaminants!

Clogged / Dirty Filters

Another thing that may cause cloudy spa water is a clogged or gunked up cartridge filter element. This can easily be treated by hosing down the spa cartridge filter elements. And for tougher gunk and oil build-up (which is probably the case 90% of the time) a good soaking overnight in some filter cleaning solution may be needed. It’s also good practice to visually check your filter for any tears or damage, and if you find any, be sure to replace it as soon as possible.

Do you want an affordable spa filter replacement that functions as good (or even better than!) the branded ones? Check out our guide on how to find the perfect cartridge filter element here.

High or Low Alkalinity

Alkalinity or your pH levels is also one thing that can cause cloudy water in your spa. Too high and you may experience cloudiness, too low and it can cause both cloudiness and your spa water having a brownish tinge! The fix for this is quite simple, simply test your spa water with some test strips and adjust the alkalinity and pH levels up or down as required. A low or high pH level in your spa can also lead to skin irritation so it is worth noting that even if your spa water is clear but you’re feeling some sort of irritation then check the pH levels and that may be the culprit!

Old Water

Even if you’re really religious in keeping your spa water balance, there will become a time where no matter what you do, it will turn cloudy! Many spa manufacturers will recommend changing out your spa water every 3 to 4 months, and you know what? We agree with this! Unlike swimming pool that can go for 5 years without a full water change, your spa water takes a beating because of the limited volume! Don’t think about changing your spa water as a waste of resources, think of it as giving your spa water a refresh! And changing out your spa water will also give you an opportunity to give your spa surfaces a full wipe down, taking off any grime and dirt that may be stubbornly stuck on your spa surfaces.


Now that we know what causes spa water to become cloudy, we can pre-empt cloudiness by taking the necessary steps to stop it from occurring in the first place. So in a nutshell:

  • Keep your spa water balanced
  • Regularly check your filters
  • Check your salt water chlorinator (if using)
  • Replace your spa water every 3-4 months
  • Flush the pipes twice a year
  • Shock the spa after heavy usage


If you stick to this maintenance schedule then cloudy spa water will be a thing of the past! No more guessing why your spa is cloudy and no more surprises waiting for you whenever you pull off the spa covers! Suffering from cloudy water in your pool or is your spa cloudiness getting out of hand? We have a water clarity guide here that you can refer to for more information.

Do you have any questions about this topic or the featured products? No worries, we're here to help! Drop us a question down below and we'll get back to you ASAP.

Happy swimming :)

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