How to Fix Cloudy Spa Water the Easy Guide

Michael Keenan


Hot Tub Troubleshooting

Imagine entering a spa only to realize that the water there is, well, cloudy. If you’ve ever experienced cloudy water in your spa, this article is for you! We’ll teach you how to fix cloudy spa water with easy steps such as cleaning the filter and managing the water chemistry.

You can also add metal sequestrants and use spa shocks weekly to keep your hot tub clean, clear and bacteria-free! Read on for more information about these methods and get ready to enjoy crystal clear spa water!

A spa does not have a lot of water but the little that there is to maintain is kept at high temperatures to avoid contamination. So, keeping cloudy water out is a top priority and this is how you do it.

fixing cloudy hot tub water

Quick Answer:

Cloudy spa water can be caused by things including unbalanced water chemistry, algae and tree seed pods, metals in the water, insufficient sanitizer, dirty filters, and biofilm. To fix it, clean your filter, run the filter frequently, balance the water chemistry and monitor calcium hardness.

Consider adding a metal sequestrant and use shock treatments weekly to control algae. Lastly flush out any biofilm buildup with a line flush product before refilling with filtered water. Keep reading for more in depth information.

What Causes Cloudy Spa Water?

Typically, a home spa can handle about 400 gallons of water which is kept hot in the range of 98 to 102 degrees Fahrenheit. This is a small amount of water but has great potential as a breeding ground for bacteria like Legionella if the water chemistry is off.

And that is just one of the problems. Here’s a few other things that cause cloudy hot tub water.

Algae and Tree Seed Pods Are the Enemies

If you leave your hot tub uncovered in your backyard, there are a lot of ways for algae and things like tree seed pods ending up in there. Dead leaves and grass clippings are no picnic either. Even if you sanitize the water, there is only so much chlorine or bromine can do.

When these natural agents attack your spa, they mess with your filter and circulation system which damages your hot tub and leads to cloudy spa water.

Algae is another enemy that grows in spa water when the water chemistry is poor or your maintenance is less than stellar.

cloudy water

Check Your Water Chemistry

Balancing the water chemistry in your spa is priority numero uno. This takes a little work but it’s not impossible. You need to start by looking at the pH levels.

If it is more than 7.6, you will notice scales in the water and your sanitizing practices won’t be effective. So, bring it down and it should be fine.

You must also keep an eye on the water’s alkalinity. If it is higher than 150 ppm, you will notice scales in the water. This also tampers with the pH levels. So, you need to keep alkalinity under control.

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The other thing to care for is calcium hardness. That needs to be between 175 and 250 ppm. Otherwise, we are back to scale formation in the spa.

Get in the habit of regularly testing your hot tub water – it should be a major part of your hot tub maintenance program.

Learn how you can manage a hot tub without using chemicals – or at least reduce your chemical use. It’s worth a look!

Avoid Water with Metals

Metal in household water is nothing to worry about for laundry and cooking purposes. But in a hot tub, it can be a nightmare. If you fill your spa area with water that has a lot of metal, it messes with the water chemistry and stains your spa.

Not Enough Sanitizer

If your spa has seen more than the usual number of people, it will have a lot more residue like body oils, shampoo residue and sunscreens on the surface. Make sure you use enough chlorine or bromine to clean the spa. Otherwise, you will risk hosting a gathering of bacteria and algae causing the water to cloud.

If you are not happy with the water quality from using chlorine or bromine alternative hot tub sanitizers are available. These are popular with people with sensitive skin.

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Don’t Forget About Biofilm

Biofilm is a slimy and sticky layer that forms on top of hot surfaces and plumbing spaces. It’s like plaque on your teeth and causes just as many problems if not more.

Biofilm is essentially bacteria residue that can eat away the surface it is on. It makes the water cloudy but also makes room for bacteria like Legionella and E. coli. In fact, the film protects the bacteria from disinfectants and sanitizers.


Dirty Spa Filters

This one is a bit obvious. A good filter makes sure large particles get sucked into the system so that they can be eliminated. This is very useful with larger debris material that the sanitizer alone cannot take care of. So, if the filter is dirty, those particles might just stay in the spa water or on the surface of your spa contaminating your water.

Find out how to clean white water mold from your hot tub here! Some great tips and information.

How to Fix a Cloudy Hot Tub

If you have gone into a full panic after looking at the list of things that could tinker with the sanitation of your spa and the sanity of your mind, you can relax. We also have easy ways to fix the problem.

Addressing the problem as soon as possible is the best way to keep your spa from getting stained. It also helps avoid scale formation on the surface of the spa.

A lot of people like to use clarifiers as a solution to all their problems. But that is only a quick fix and not an actual solution. Instead, here are some things you should do.

Clean the Filter

This is the first step. Your filters need regular cleaning to avoid cloudy spa water. Don’t hesitate to pull it out and check it. Depending on what it needs, give it a good cleaning or replace it.

Whether it is sunscreens or scaly water and algae, your filter is the first thing that needs maintenance even before the water gets cloudy.

Run the Filter

Spa water needs to be filtered a couple of times for at least an hour every single day. This is non-negotiable. Whether you have an automatic mechanism or choose to do it manually is up to you.

Just make sure the contaminants are cleared so that the chlorine or bromine can do their job well. Remember to do this more often if more people are using the spa.

dirty spa water

Learn to Manage Water Chemistry

The first step here is to look at the chemicals and see if any adjustment is needed. If they are at the levels they need to be, make a maintenance schedule for your hot tub and other spa equipment.

Make sure there is a specific part that includes water care. This takes care of water chemistry, which as we have seen before, is a top contributor to cloudy spa water.

Apply Spa Shock Regularly

Algae and other contaminants can be controlled by giving the spa a good shock. This can be one of the steps in your hot tub maintenance plan. You must do this weekly and can be even more frequent depending on the capacity and usage of the spa.

See also my guide on how often to change your hot tub water – it explains more about bather load and contaminants.

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Consider Adding a Metal Sequestrant

Now, you will need a sequestrant if you find that your water source is injecting metals into the spa. It is one of the ways of maintaining your hot tub. This must be in addition to the solutions and sanitizers you use to keep the spa surface and the water in it clean.

The sequestrant will make sure the metals in your water do not lead to scale formation that causes cloudy water.

In fact, if metals in the water is a problem, you will need a sequestrant that specifically addresses this issue. It binds itself to the metal and stops it from oxidizing.

This in turn stops the discoloring of water and the spa itself. Add the sequestrant each time you drain clean and re-fill the hot tub. And do so with filtered water. This must be part of the weekly water care plan.

Draining and Refilling

Typically, hot tub water should be changed every three months or so. Despite that, if you notice cloudiness in the water and are not able to get rid of it, you need to buckle down and drain and clean the hot tub.

Start by getting a line flush product and a new filter. If you don’t have to replace the filter, that will just be a spare.

Drain your spa and clean its shell thoroughly. Fill it up again using a hose filter. After that, add the metal sequestrant and shock the water to make sure the water chemistry is on point. This way, your hot tub is good as new.

If You Have a Biofilm Problem

Biofilm can cause white looking flakes in your hot tub. I have a guide on how to remove white flakes from your hot tub here, have a read to learn more.

This is not unusual and here is the solution. The best way to get rid of biofilm on your spa is to add a line flush product to the water. Check the product for instructions but typically, you must let it settle down for about 30 minutes.

You will notice some foam in the hot tub while this happens which is normal. That is the process of the biofilm and similar debris leaving the plumbing area and the surface of the spa. Then flush the spa lines and proceed to change the water.

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Travel Story!

My family and I had just moved from Koh Samui in Thailand to a new property in North Bali (the best part by the way!). We had done our research as usual and picked out a great looking rental house with a nice pool and hot tub. Let’s just say that when I removed the hot tub cover I got a little surprise!

The water wasn’t just cloudy – It was thick!! It looked like it had been sitting and stewing in the heat for months. Thankfully, I din’t need to fix it – they sent in a pro.

The Bottom Line

Taking care of your hot tub and keeping the water chemistry balanced is essential for avoiding cloudy spa water. Regularly cleaning and replacing filters, adding a metal sequestrant, shocking the water, and draining/refilling are all important steps to keep it in tip-top shape.

Don’t let algae, tree seed pods, metals, biofilm or debris get in the way of having a perfect dip in your spa – be vigilant with regular maintenance!

It’s easy to fix cloudy spa water if you have a good routine in place. Get the right kind of equipment and do the regular checks as mentioned above and it will go right back to being the heaven that it is meant to be. Happy cleaning!

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!