
The feeling of deep peace and contentment you can experience in a hot tub can end abruptly by the sight of anything (other than bubbles) floating around in your tub with you! But it can be confusing to know exactly what chemicals you need for your hot tub.
To help to keep your hot tub itself sanitized and the water sparkling, you’ll need the following chemicals:
- Sanitizers
- pH increasers and decreasers
- Scale inhibitors
- Defoamers
- Clarifiers
- Filter cleaners
These chemicals will help prevent algae and bacteria buildup.
To keep your tub in tip-top condition and yuk-free, you’ll want to clean it regularly. Hot tub cleaning products are specifically designed to kill bacteria and dissolve any dirty rings around the rim of the tub. Below you’ll find some of our favorites.
Pro Tip: If you don’t like the idea of soaking in harsh chemicals try products from Ecoone that use more natural enzymes and fewer chemicals, but still get the job done! See Ecoone’s hot tub cleaning agents on Amazon.
The Essential Chemicals for Your Hot Tub
If cleaning your hot tub sounds like a full day job, never fear; with the right products, you can have a sparkling, sanitized tub in about 3 hours! (And if you’ve got a swim spa, you’ll want to care for it with the same sort of chemicals as a hot tub.)
Sounds too good to be true? Let’s see what chemicals you need for a hot tub and which products work great.
A quick caution: when using sanitizers in your hot tub water, never mix them! If you want to swap from one sanitizer to another, first perform a line flush, drain the tub, and then clean your hot tub before adding a different sanitizer.
Water treatments prevent all sorts of nasty germs and bacteria from living and breeding in your hot tub water. Read through my article on Why Jacuzzi Jets Make You Itch to find out what happens if you choose not to treat your hot tub water as you should!
First, let’s discuss the essential and best chemicals for hot tub you’ll need and what each one does:
1. Chemical Sanitizers
To remove the build-up of bacteria and disinfect the water, you need to use a chemical sanitizer to keep the water clear and clean. A sanitizer removes nasty germs from your hot tub water.
If you don’t use a sanitizer in the tub, bacteria, algae, and nasty germs will thrive in the warm water and take over your relaxing space!
There are three effective sanitizers that you can use in your hot tub to eliminate germs, algae, and bacteria, each with its own benefits. (And inflatable hot tubs also need chemical treatment, too.) Be sure to choose the sanitizer that works best with your particular filtration system:
Chlorine Sanitizers
Chlorine is an oxidizer that effectively eradicates contaminants in the water. The pungent smell that we all associate with chlorine results from a chemical reaction between chlorine and water that produces chloramines. Chloramines cause the odor from the water!
Chlorine is available in tablet form or floaters to make caring for your tub water simpler. Still, when using these products, you will have to monitor the chlorine levels in the water more often and remove the products once the water is balanced.
The best and easiest way to control algae growth, destroy most organic contaminants and kill nasty bacteria in the water is by using chlorine granules.
Granules work so well because they provide a slow release of chlorine into the water. Chlorine granules are stabilized to protect it against UV radiation from the sun and increase the product’s shelf life.
Recommended: Spa Selections Chlorinating Granules

A fast-acting, easy to use, chlorine granule that destroys and prevents algae growth, kills bacteria and other organic materials, and leaves no sediment on the surface of your hot tub!
Simply add to your hot tub after use in the evening while the filter pump runs and leave it to soak. What could be easier?!
Bromine Sanitizers
This chemical is an alternative to chlorine, as it also works to keep hot tub water clean. Bromine ionizes the water and breaks up unwanted particles.
It is different from chlorine and is not the best choice for mineral systems, but it can be less irritating than chlorine if you have sensitive skin.
Bromine granules and bromine tablets take longer to dissolve in hot tub water, and it can leave you feeling like it is sticking to your skin and swimwear. If you do use bromine in your hot tub water, always make sure that you rinse off your skin and swimsuit when you get out of the hot tub.
Oxygen Sanitizers
Oxygen is a milder solution to chlorine and bromine and is designed for use in a hot tub for those with sensitive skin. (And by the way, if you do have sensitive skin, you might also consider using bamboo towels. They are the best for people who get easily blotchy and splotchy.)
You’ll need to use oxygen tablets in conjunction with oxygen liquid. When used together, they kill germs and bacteria in your hot tub water.
The advantage to using oxygen tablets in your hot tub is that one 0.7 oz (20 gram) tablet should last one week in 396 gallons (1,500 liters) of water. Add another tablet to the water each time you enter the hot tub to get the balance right.
2. pH Decreasers and Increasers

In hot tub speak, pH increasers and decreasers are commonly known as “balancing chemicals.”
Your hot tub water should contain certain chemicals which need to be balanced within a specific range:
- pH between 7.4 and 7.6
- Total alkalinity between 80 and 120 ppm
- Calcium hardness between 150 and 250 ppm
If all three of the above chemicals readings are within the correct range, your hot tub water is balanced, free from germs and bacteria, and safe for you to soak in!
Test the water in your tub regularly to maintain the correct levels. The more you use your hot tub, the more you should test and treat the water.
Recommended: SpaGuard PH Decreaser and SpaGuard PH Increaser
The SpaGuard pH decreaser will reduce both the alkalinity and pH levels to an acceptable range. This will ensure your equipment can continue to function normally and will help prevent scale buildup.
If the pH and/or total alkalinity are too low, add the SpaGuard pH Increaser to raise the levels back to the norm. When pH levels are too low, the water feels acidic and can sting if it gets in your eyes or nose.
3. Scale Inhibitors

You might know if you have scale in your hot tub the second you enter the water; it can grow on the sides of the tub and feels like sandpaper!
But the mineral buildup can also hide in the plumbing system and the heating elements, making it harder to spot and causing unseen damage to your hot tub.
The best way to remove scale build-up and to prevent it from returning to your hot tub is by draining the tub, cleaning it with specialized cleaning products and keeping the chemical levels in the water properly balanced.
Recommended: Spa & Hot Tub Scale Remover
This product is a specialized scale remover designed to attack and defend against lime and scale buildup. Available in a handy 32 ounce (900 ml) spray bottle, this product can be used weekly to keep your hot tub sparkling clear and clean.
This product is likely to exceed your expectations and do more than its fair share to keep your hot tub sparkling clean!
The Spa & Hot Tub Scale Remover will:
- Remove existing scale formulation
- Prevent new scale formation
- Prevent calcium build-up and keep the water clear
Simply drain the hot tub, and spray the surface with a mixture of 8 ounces of scale remover mixed with ½ gallon of water. Let the solution sit and work for 10 to 15 minutes and rinse off.
4. Hot Tub Defoamers

Excess foam is a common problem in hot tubs. Thick foam caused by soap, deodorant, oil, shampoo, and lotion residue can accumulate on the water’s surface in the hot tub, causing an unhygienic mess!
Low calcium levels in the hot tub water can account for too much foaming and also decrease the surface tension in your water, making it easier for oil and water molecules to mix.
There are various ways to treat and eliminate hot tub foam. Some chlorine shock treatments will only break down the foam, while others, called “defoamers,” will break down the foam and treat the root cause.
That said, be careful how much defoamer you add to the hot tub water as using too much can cause cloudy or milky water!
Recommended: Pool & Spa Anti Foam Defoamer
This super-concentrated water silicone defoamer does not cloud the water in your hot tub or leave any oily residue in the tub. This solution prevents foam formation in the water.
Available in 32 oz, 1, and 4-gallon containers, the Pool and Spa Anti-Foam Defoamer has a 30-day money-back guarantee; some hot tub owners have even used this product to clean out dishwashers and washing machines with excellent results!
5. Hot Tub Clarifiers

If you’ve just cleaned and sanitized the hot tub, but the water still looks cloudy and dirty, it could be because the water balance is incorrect or simply because of dirty filters.
Check and adjust all the chemical levels first before adding any other chemicals to the water. A hot tub clarifier should be added to your hot tub water weekly to prevent clouding. A clarifier works to collect dirty particles together that are then removed by the filter.
You could also shock the hot tub water once a week with a non-chlorine shock treatment to prevent cloudy water.
Recommended: SpaGuard Water Clarifier
Use 2 Tbsp per 300 gallons on first use or 1 Tbsp per 300 gallons for weekly maintenance. The SpaGuard Water Clarifier will help accumulate small particles of debris together so they are then large enough to get caught in your filter. This product will not affect your hot tub’s pH level.
6. Hot Tub Filter Cleaners

Filters work hard to keep your hot tub water clean, clear, and sparkling! Filters are responsible for removing dirt and grime from the water. Dirty filters can cause restricted water flow and even cause the hot tub to shut down!
A standard hot tub filter should last a least a year. However, this will depend on how often you soak in your hot tub and how many people use it.
You’ll want to soak your hot tub filters once a month in a specialized filter cleaner. This helps remove all the dirty particles.
Recommended: AquaDoc Hot Tub Filter Cleaner Soak
While some filter soaks require you to soak overnight, this one is a 60-minute soak. It will take grease, suntan lotion, dirt and scale out of your filter and increase the lifespan of your spa.
What Do I Need to Do the First Time I Use the Hot Tub?

If you are a newbie first-time hot tub owner, there are specific steps to follow before using the tub for the first time. You’ll need to be sure you have the correct balance of chemicals in the water. To do this:
- Check that all the plumbing has been installed correctly according to the owner’s manual.
- Clean the interior of the tub using a non-abrasive cleaner (do not use common household cleaners) and a clean towel.
- Install the filter cartridge and fill the tub with clean water.
- Switch on your tub and check that the jets are working.
- Test the water and add chemicals.
You’ll want to keep the water clean but you’ll also need to routinely clean the tub and filters. For help with that read my post “Yuck! How to Get Rid of Black Flakes in a Jacuzzi“
Hot Tub Starter Kit

The range of products available for cleaning and sanitizing your hot tub can be overwhelming, especially if you’re a new hot tub owner! To help you out, we’ll suggest some of the best hot tub chemicals to help keep your hot tub clean and user-friendly.
A Hot Tub Starter Kit is an all-in-one solution for anyone who has discovered the joys of a hot tub at home and is using one for the first time! Plus the great thing is that the products in this kit don’t contain harsh chemicals.
The kit generally includes everything that you need to maintain your hot tub for at least one month:
- Sanitizer
- pH balancers
- Clarifier
- Testing strips
Last Thoughts About Hot Tub Chemicals
Of course, keep hot tub chemicals away from children and pets. Store hot tub chemicals in a cool dry place.
And as a rule of thumb, don’t enter the hot tub for at least 12 hours after adding sanitizers to the water. This will allow the products to sanitize your tub correctly.
Once you’ve got your hot tub bubbly and beautiful, you’ll need to keep it clean. This post will show you exactly how.
And keeping your hot tub at a consistent temperature can help prolong its longevity.
If you live in a colder climate, learn to winterize your hot tub the right way.
Finally, after you’ve balanced the chemicals and cleaned your tub, you’re ready to enjoy the relaxing haven in your home. To enhance the fun, check out the 10 Coolest Gifts for Hot Tub Owners.
Tags: clarifier, enzymes, essential hot tub chemicals, filter cleaner, hot tub, hot tub defoamer, hot tub sanitizers, pH decreaser, pH increaser, scale inhibitor