Skip to Content

Hot Tub Water Green: How to Clear It Up Fast

Hot Tub Water Green: How to Clear It Up Fast
This article may contain links from our partners. Please read our Disclaimer for more information.

A hot tub water bath epitomizes relaxation and fun. With its powerful jets that massage you, it is the perfect hydrotherapy after a long day.

But imagine entering your hot tub and seeing your spa water have a green look to it. It’s off-putting, isn’t it? You might wonder why it looks the way it does and what you can do to fix it and prevent it from happening in the future.

Fret not; this article elucidates everything you need to know about why hot tub water green. Moreover, you’ll find out tips to prevent it from happening again to ensure you have a smooth and relaxing hot tub experience here on.

Why Is My Hot Tub Green? 8 Causes

To know how to get rid of green hot tub water, you need to know what causes hot tub water to turn green. Following are the major cause behind this occurrence:


If you notice your spa water being green, one of the causes is algae. However, this is rare. Algae require sunlight, being an aquatic plant. So, it is commonly found in outdoor pools, but sometimes it does infect hot tubs as well, especially if there is adequate sunlight.

Algae cause green spa water. It forms a slimy layer and can come as yellow algae, pink algae, or black algae. You need to ensure you keep your hot tub clean to avoid this.


Your hot tub might have green water due to pollen sticking to its sides. This is unavoidable as the wind carries pollen and deposits it in your hot tub.

However, cartridge filter systems can remove pollen deposits. If that malfunctions, you’ll have a persistent case of green water due to pollen build-up.

While pollen build-up is harmless, it does make your hot tub look unhygienic and uninviting.

Low Chlorine

Often, the chlorine levels in your hot tub reduce over time. This happens due to heat breaking up the chlorine. It also occurs when a biofilm, group of microorganisms like bacteria, protists, and fungiform.

Low levels of chlorine are an invitation to a cesspool of bacteria. This, in turn, causes your hot tub water to turn green.

Plus, it becomes unhealthy for you to enjoy a hot tub session when there are low chlorine levels, as you’ll invite diseases or dangerous bacteria.

Low PH

Suppose your hot tub has a pH imbalance; this can cause the hot tub water to acquire a green tint too. A low PH means the water is too acidic, and it can erode the plastic and metal equipment.

Plus, when the pH level is low, it can cause copper to dissolve from the heating element to your spa water. Note that even alkaline water with a high pH level can dry out your skin. So, you need to maintain a neutral pH level in your hot tub.

No Hot Tub Cover

When your hot tub is not in use and if you don’t use a hot tub cover, you are most likely inviting trouble. Not using a hot tub cover means your hot tub water is exposed to sunlight, which is basically an invitation for algae. Moreover, exposed hot tubs break down the sanitizer quickly and lower chlorine levels.

Damaged Filter

Hot tubs generally come with filters to clean out pollen, algae, and other chemicals. Suppose you haven’t cleaned or changed it in a while or it has become damaged. This can result in you having cloudy water, green tinge water, or clear green water.

Chances are the damaged filter can cause your water to turn into other colors too!

Not Enough Sanitizer

Suppose your chlorine or bromine levels are low in the hot tub water. This means your sanitation levels reduce drastically, and you will not have clean hot tub water. Rather, you’ll find water with a green tinge, and it will be unhealthy for you to have a hot tub experience in that situation.

The sanitation chemicals should be of proper levels to prevent green water.

Copper Oxidation

Copper oxidation causes your spa water to be green. After you shock your hot tub, the water turns green because copper oxidation occurs. The bad news is if you leave this untreated, your hot tub will stain and look ugly.

How to Get Rid of a Green Hot Tub Now

Now that you know the causes and ramifications of green water in your hot tub, you’ll want to know how to get rid of it. If you find green water in your spa, follow the steps below to address the situation and rescue your hot tub.

Read our related post on Hot Tub Troubleshooting!

Check Filter and Replace as Needed

The filter ensures the circulation of warm water in your hot tub. It also has a filtration system that sucks dirty water and filters it to kill bacteria and get rid of dirt, leaving you with warm spa water for the perfect hydrotherapy.

However, if your tub water is green, you might need to check your filter cartridge and clean or replace it. Depending on the damage, you can merely deep clean your filter. Alternatively, you can swap it or replace it with a spare filter.

Use a Hose Filter

Suppose you use a garden hose to fill your tub. In such a case, we recommend you consider using a hose filter. A garden hose might not be clean and can cause your hot tub water to turn green.

The easiest way to fix this issue is to use a hose filter so that only clean water enters your tub, and then you can adjust the levels.

Balance the Water and Shock It

To fix green water issues, do a hot tub shock treatment to balance the chemicals in the water. Shocking the water in a hot tub means adding plenty of chlorine or non-chlorine shocks. This will break down the organic waste that causes green, cloudy, and odorous water.

Moreover, shocking the water ensures that your tub doesn’t have an algae problem.

Another thing to note is that you must maintain the PH levels between 7.2-7.6, and the total alkalinity should be between 80-120ppm only.

Test the Water

If your spa water is green-colored, you might want to test your water. See that the total alkalinity is maintained between 80-120 ppm, as mentioned above. Also, ensure the total hardness is 150-300 ppm, and the Ph should be between 7.2-7.6. Plus, you must maintain the total dissolved solids between 500-2000ppm.

Test the water to ensure there is no chemical imbalance. You can use test strips to check the chemical balance. This will help you determine whether you need to add chlorine, filter cleaner, or make another adjustment to balance the water chemistry.

Drain and Clean the Hot Tub and Cover

A good option, as a last resort for you to get rid of green water from your tub, is to drain out the water and wash your hot tub thoroughly. Plus, this will ensure you get freshwater that is algae-free into your tub.

Refill the Hot Tub

After draining the hot tub, you can clean the spa shell with a strong bleaching solution and eliminate any remaining algae. Then refill it with clean water and add free chlorine while ensuring the total chlorine level is between 3.0-4.0 ppm.

Is Your Hot Tub Another Color?

What if you step out to soak in your spa shell and find that there is another color instead of green water. Read on to know the ramification of different spa watercolors.

Yellow Hot Tub Water

If your spa has yellow water, it could be for the following reasons:

• There are yellow algae

• Excess pollen in springtime

• High bromine levels

• Iron oxides are present in the water

You’ll need to replenish the sanitizer levels, do a chlorine shock, and pre-filter chemicals, minerals, and metals out of the water that you use for your tub to avoid a yellow color.

White Hot Tub Water

White-hot tub water results from high calcium or alkalinity, air bubbles in the system, or ineffective filtering or pumping. Plus, contaminants from soap, hair products, cosmetics, and similar additives can make your spa water turn cloudy, cause hot tub foam, and make it white.

White mold is a type of bacteria that can cause white water if proper hot tub maintenance hasn’t been done.

You must raise the chlorine levels to combat white water. Plus, it would help if you replace the spa filter and rinsed your hot tub shell and spa cover with a strong bleach solution.

Pink Hot Tub Water

Pink algae are related to the white mold family. It’s a form of bacteria that makes your spa water look pink. The good news is this is uncommon.

Suppose you find pink hot tub water; use shock treatment and use purge product to clean the crevices and lines. Plus, ensure you check and replace your filtration system. Also, use a hot tub cleaner and a strong bleach solution to clean your spa shell and other spa items.

Hot Tub Water Green: Preventing It Moving Forward

Prevention is always better than cure, isn’t it? So, here are a few tips for preventing dirty or colored water in your hot tubs. First and foremost, you need to undertake hot tub care to prevent foams from forming. Then follow the below tips.

Shower Before Jumping in

When you shower before jumping in, all the cosmetics, deodorant, moisturizers, and any hair product you have applied will wash away. This will prevent hot tub foam. Plus, it will lower any contamination to your hot tub.

Keep It Covered

The best way to prevent green or other colored water and undertake optimum hot tub care is to keep your spa covered.

Irrespective of whether your hot tub is indoors or outdoors, it’s best to keep it protected. You’ll prevent exposure to sunlight, algae bloom, pollen, debris, dust, and other organic material.

Check the Filter

Ensure you check the filter in your hot tub regularly. It’s best to deep clean your filtration system as a routine practice. Moreover, you must replace your filter when it starts slowing down.

Checking your filter regularly will ensure the prevention of algae, bacteria, and other dirt that causes green water.

Clean Routinely

It goes without saying that you must clean your spa regularly. Drain and refill it periodically to ensure freshwater with optimum water chemistry. You’ll be able to prevent algae growth if you clean your spa regularly. Moreover, your hot tub experience will be phenomenal in a sparkling hot tub.

Test and Balance the Water Regularly

Test the sanitation levels and ensure the pH balance of the water is maintained regularly. Take a few hours out in a week. If you do this, you will prevent green water easily. Suppose you don’t test and balance your water regularly; you’ll find your water unbalanced and a welcoming ground for bacteria, fungi, algae, and more. So testing and balancing your tub water is key!

Hot Tub Water Green FAQ

Here are some frequently asked questions answered in brief regarding green hot tub water.

How Do I Get Rid of Green Water in My Hot Tub?

Get rid of green water by deep cleaning your spa items with a strong bleaching solution. Replace the filter and give your tub water a shock. Test and balance your water. Ensure your copper pipes are clean and don’t leach excessive metals into the water.

Is Green Hot Tub Water Safe?

No, green hot tub water is not safe. It is a breeding ground for viruses and bacterial infections. Get rid of any form of colored water and deep clean your spa before getting in.

Should Hot Tub Water Have a Green Tint?

Ideally, it shouldn’t have a green tint. If you find your spa water having a green tint, check the chemical balance.

How Do I Get My Hot Tub Water Clear?

The best way to get your hot tub water clear is to drain and refill it. You’ll be able to enjoy your spa better.

Summing up Hot Tub Water Green

Soaking in a hot tub is a relaxing and rejuvenating experience. You don’t want to deal with green or colorful water that can potentially harm you. However, sometimes it is unavoidable. So, you need to get rid of green water using the tips given in this article. Alternatively, take preventative measures to ensure you never have to deal with such situations.

So, take due care of your hot tubs to have the ultimate hydrotherapy experience.