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  • Writer's pictureAqua Warehouse

How soon can you use a hot tub after adding chemicals?

Updated: Feb 28, 2023

Common hot tub chemicals like chlorine and bromine are essential for maintaining fresh water in your hot tub. Both chlorine and bromine help to maintain balanced hot tub water chemistry, and even with a hot tub filter you still need a sanitizer in the water.

However, if you don't use chlorine and bromine the right way, it could lead to issues like skin irritation for peple with sensitive skin. As a hot tub owner, you probably want to use your hot tub regularly. But how much chlorine should you add and how long should you wait before getting into the tub after adding the sanitiser?

In this article, we look at hot tub safety and how long it takes for your hot tub to be safe to use after treating it with chlorine or bromine.

Do you need to wait after adding chemicals to your hot tub?

Avoid using your hot tub immediately after treating the water with chemicals. Allow some time for the chlorine or bromine to disperse in the water. An extremely high bromine or chlorine level in the water, such as immedtaely after you shock a hot tub, can harm you in more ways than one if you get into the tub straightaway.

Whether it is a non-chlorine shock or chlorine shock treatment, a general rule is to avoid hot tubbing after treating the hot tub's water with chemicals. Just follow the specific product instructions carefully. Shock dosing also helps to eliminate organic contaminants in your hot tub.

How long should you wait to get in your hot tub after adding chemicals?

We recommend you wait from 30 minutes to 24 hours before you get in a hot tub that has been treated with chemicals. Adding chlorine tablets is one of the most effective methods to kill bacteria but it can be quite harsh on skin.

This is why you should regularly check your hot tub's chemical levels with a test strip or other method to know when the water is at a safe level for you to soak in.

What chemicals are used for a hot tub and how long should you wait for each one?

There are different chemicals you can add to your hot tub including pH decreasers, pH increasers, sanitisers, and many others. We will be looking at the two most popular ones.

Hot tub sanitisers - chlorine and bromine

Before you can get a full grasp of how long to wait before entering your hot tub after adding chemicals, you first need to know the differences between bromine and chlorine. These chemicals help to keep your hot tub water fresh and prevent you from developing health issues.

The Differences Between Chlorine and Bromine

Chlorine does not like warmer temperatures, which is why it is less stable when used in hot tub/spa water. This is why you mostly find chlorine in swimming pools and bromine widely used in hot tubs.

Unlike chlorine, bromine has no stabilising partner chemical such as cyanuric acid, so it lasts longer in warm water, so you spend less time when you apply it. Also, bromine will dissolve slowly in warmer water, meaning that you don't have to add it as frequently as chlorine and you will still get crystal-clear water.

Chlorine is less expensive than bromine, but most people always look for the more effective option and that would be bromine, as it is better for skin. You don't need to worry about understanding confusing water chemistry to learn more about chlorine vs bromine.

How long after putting chlorine in can you get in a hot tub?

You should allow about 30 minutes minimum after adding chlorine before you enter the water. Also, after adding chlorine, ensure that you leave the hot tub cover off to allow the chemical vapors and chlorine smell to escape.

We recommend testing your spa water before getting into the hot tub to ensure you added enough chlorine and it is not in excess.

Can you Enter a Hot Tub Faster After Adding Bromine?

You will be able to soak in your hot tub sooner if you use bromine instead of chlorine. Bromine's safe levels are 1-3 PPM, while the safe level of chlorine is 3-5 PPM.

One of the main reasons why you can enter hot tubs sooner if you use bromine is because it is less irritating than chlorine.

Hot tub shock chemicals

Shocking your hot tub is a great way of killing bacteria and also removing other contaminants. A hot tub shock is an oxidizing agent. Follow instructions (the manufacturer's instructions preferably) when shocking your hot tub.

How Long To Wait After Shocking your Hot Tub?

A chlorine or bromine shock will still affect the levels of the chemicals in the hot tub water and that is why you still have to allow time for the chemicals to settle before you get in.

Alkalinity increaser

Water chemistry is as important as keeping your hot tub's water clean. If you don't have the right level of alkalinity in your hot tub, it can destroy the look of the water. A low level of alkalinity in your hot tub can cause serious problems as the acid could prove to be a handful for the water. If your hot tub is beginning to develop some issues, then you might need to increase the alkalinity. Learn more about hot tub water alkalinity.

How Long To Wait After Increasing Alkalinity in your Hot Tub?

You will need to wait for at least 24 hours after increasing the alkalinity in your hot tub before you can use it. By increasing the total alkalinity, you can better maintain the pH level of the water.

pH increaser

This is a chemical product that helps increase the pH level of the water. Ideally, the hot water in your hot tub needs to have a pH level of 7.0. Safe levels still fall within the range of 7.2 to 7.8. Don't risk soaking until you adjust the water's pH level and ensure a perfect balance.

How Long To Wait After Increasing Ph in your Hot Tub?

The recommended waiting time for using your hot tub after adding a pH increasing product is at least two hours. This is to give the chemical ample time to properly increase the pH level and not make the water overly acidic.

pH decreaser

A pH reducer is introduced when there are high pH levels in your hot tub. Overly high levels could leave scale on the pipes, jets, filters, and plugs. Balancing the pH level correctly is imperative.

How Long To Wait After decreasing Ph in your Hot Tub?

After reducing the pH level, you need to wait for about two hours before using your hot tub.

Calcium hardness increaser

It is a great idea to add a calcium hardness increaser to a hot tub. It is a product that helps to maintain the proper calcium hardness levels in a hot tub.

Line flush cleaner

A line flush cleaner helps to sanitise your hot tub by eliminating stuff like dirt, grime, heater scale, and any residue of body oils.

How long after adding chemicals to the hot tub can you test?

After you add chemicals to your hot tub, you should wait for a few hours before doing a test. Then, if you want to retest the water, wait for at least 24 hours before taking another water sample. The water test will check the calcium hardness, chlorine levels, bromine levels, total pH and alkalinity levels.

High chlorine levels can impact the clean water and might also cause health problems (possible respiratory issues), this is why you should always test. You can also remove the spa cover as a way to speed up the process of lowering the chlorine levels.

How Long After Increasing Chlorine Can You Test your Hot Tub?

You should wait for about 2 hours or more but not more than 12 hours as this would be the perfect time to test and be on the safe side.

How Long After Increasing Bromine Can You Test your Hot Tub?

You get the best results if you wait for at least 2 hours to allow the water to stabilise after adding the spa chemicals.

Can you use a hot tub without chemicals?

You can definitely use your hot tub without adding chlorine or bromine sanitizer. There are people that might not want to add chemicals to their hot tub water because of one reason or the other. You can use non-chlorine shock or other means to generate free chlorine.

If you don't add chlorine or any other chemical to your spa water, you can still keep the hot tub water fresh but it will require some serious hot tub maintenance. To discover the best way, read our guide on running a hot tub without chemicals.


"How soon can you use hot tub after adding chemicals?" is a very common question. Adding chlorine or bromine is a very effective way to sanitise any hot tub/spa and keep the water fresh and clean. But, it is easy to add too much and make the tub/spa unsafe to soak in. It is advisable to use test strips to check the bromine and chlorine levels on a regular basis. Adding more chlorine than required could lead to issues like itchy skin and eyes, or respiratory issues.

If the chemical levels are extremely high, you can get them back to within the recommended range by removing the hot tub cover and letting direct sunlight break the bromine and chlorine down as you run the hot tub jets or you can also use a sanitiser remover. Always make sure you use a test strip to check the chemical levels of your hot tub.




Jess Court

I'm Aqua Warehouse Groups Marketing Officer - overseeing all things news worthy in the hot tub industry, with tips and tricks that are bound to make a splash.

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