Best Hot Tub Chemicals to Use (Everything You Need to Know)

Learning what chemicals go into your hot tub was probably the last thing you were worrying about when you bought your unit.

You probably went ahead and first considered how many persons can fit into the pool and how easy it is to use before even thinking about how to properly take care of your blow up hot tub.

However, it’s important to know what chemicals are crucial in keeping your hot tub clean, safe and long-lasting.

The good news is you don’t need a degree in Chemistry to familiarize yourself with how to use chemicals. This hot tub care guide will help you get started on everything you need to know about hot tub chemicals.

Why Use Chemicals in a Hot Tub?

Chemicals are by far the most cost-effective way of cleaning and maintaining the quality of water in your unit.

By killing the bacteria in the water, these chemicals make it more comfortable for us to soak in the tub’s water. It also helps in keeping your filtration unit working effectively.

hot tub disease
Hot Tub Folliculitis

Using chemicals is quite crucial because our body tends to lose roughly a pint of body fluids for every hour we are in the hot tub.

Everything from grime, sweat, dirt, oil and other fluids are mixed in its water. Many of the chemicals used in hot tubs are primarily responsible for keeping the water balance and sanitation of the unit.

Common Hot Tub Chemicals

Your hot tub requires several treatments for it to be safe and clean.

As such, it also needs different types of chemicals and products that help in keeping things such as total alkalinity, calcium hardness, and oxidation in normal levels.

Two of the common types of hot tub chemicals are sanitizers and water balance compounds.

Below is a more in-depth look at these chemicals:


Chemicals that are meant to kill bacteria are called sanitizers. When mixed with water, they create an acidic solution that kills bacteria in the water.

Two of the most widely used sanitizers are chlorine and bromine tablets.

Chlorine (Our Pick: Leisure Time Chlorinating Granules)

Leisure Time 22337A 56 Chlorinating Granules Spas and Hot Tubs, 1-Pack
1,034 Buyer Ratings
Leisure Time 22337A 56 Chlorinating Granules Spas and Hot Tubs, 1-Pack
  • Destroys organic contaminants to maintain clean, clear, sanitized water
  • Compatible with chlorine sanitizing systems
  • Specifically formulated for spa and hot tubs

While they are mostly used in public pools, chlorine is also an effective chemical in hot tubs. Apply 3.5 mg per Liter of water every other day or as recommended by the user manual of this product.

Maintain a chlorine level of 1.5 to 3.0 parts per million (PPM). Chlorine or bromine can be bought in 1-inch tablets or granular form that you can add to your water.

Bromine (Our Pick: Leisure Time Bromine Tabs)

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Leisure Time 45425A Brominating Tablets, 1.5 Pounds
446 Buyer Ratings
Leisure Time 45425A Brominating Tablets, 1.5 Pounds
  • BENEFITS: Dantabrom chemistry provides 10% more active sanitizer; keeps water clean, clear, and odor free
  • USE: Follow included directions for water application; Fits all floaters
  • COMPATIBILITY: Works with bromine sanitizing spa systems

Bromine offers the same sanitizing effect as chlorine, but with less harshness. The recommended bromine levels are at 3.0 to 5.0 PPM. You can use a floater for both bromine and chlorine tablets.

When using a floater, you usually load 4-6 tablets and have to wait at least 15 minutes before the tabs completely dissolve.

As a general rule, always use test strips at least once a week to ensure that the mineral and hot tub chemical levels are on par with what is recommended in your hot tub’s manual.

Water Balance Chemicals

Your hot tub or swimming pool also needs to have a balanced level of minerals and chemicals for you to have the best comfort and your tub to last longer.

Below are the four most important aspects you have to look into:

Total Alkalinity (Our Pick: SpaGuard Total Alkalinity Increaser)

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SpaGuard Spa Total Alkalinity - 2 Lb
164 Buyer Ratings
SpaGuard Spa Total Alkalinity - 2 Lb
  • Raises total alkalinity
  • Prevents “pH bounce”

The first step in maintaining your tub’s chemical balance is to check its alkalinity. It should be anywhere between 80 and 120 PPM.

You can use a test strip to check its readings. If it’s above 120 PPM, use sodium bisulfate to lower it down and if it’s lower than 80 PPM, use sodium bicarbonate to make it higher.

Calcium Hardness (Our Pick: Leisure Time Calcium Booster)

Leisure Time CB Calcium Booster Spa Care for Hot Tubs, 1 Quart
262 Buyer Ratings
Leisure Time CB Calcium Booster Spa Care for Hot Tubs, 1 Quart
  • BENEFITS: Raises water hardness to maintain a level of hardness between 150-400 ppm
  • USE: One ounce increases hardness 7 ppm in 500 gallons of water
  • COMPATIBILITY: Compatible with chlorine, bromine, ozone, and biguanide sanitizers

Calcium hardness is the measure of how soft or hard the water is. Too low and the water can be corrosive and cause staining.

Too high and it can form scales in your tub’s pipes. Tubs with acrylic finish should have 100–250 PPM, while those with plaster finish should have 250–450 PPM.

Oxidizers (Our Pick: Leisure Time Renew Non-Chlorine Shock)

Leisure Time RENU2 Renew Non-Chlorine Shock, 1-Pack
801 Buyer Ratings
Leisure Time RENU2 Renew Non-Chlorine Shock, 1-Pack
  • Non-chlorine shock oxidizer clears cloudy water and eliminates odors and contaminants
  • Compatible with chlorine, bromine, ozone and mineral purification systems
  • Buffered to prevent pH fluctuations

Oxidizers destroy waste and odor in the water and are also called shock treatments. They require higher sanitizer levels to keep the water sparkling clear.

Check your manual for proper dosage.

pH Levels (Our Pick: AquaChek Spa 6-in-1 Kit)

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AquaChek Spa 6-in-1 Test Strips Kit (50 count bottles) (2 Pack)
56 Buyer Ratings
AquaChek Spa 6-in-1 Test Strips Kit (50 count bottles) (2 Pack)
  • Fast and effective way to test your hot tub water
  • Strips test for Total Bromine, Total Chlorine, Free Chlorine, Total Alkalinity, pH and Total Hardness
  • Quick and accurate test readings

Simply put, pH is the measure of your tub water’s acidity. This should be checked last and using a test kit should be kept between 7.2 and 7.8.

Check your hot tub water pH levels after each use and apply a hot tub chemical if needed.

Importance of Hot Tub Maintenance

Unlike a pool, a hot tub is more delicate, has more parameters to monitor and requires a different treatment. Water in hot tubs is generally much hotter than that of a pool, with 102 to 104 degrees Fahrenheit and 82 degrees, respectively.

As you well know, most bacteria thrive better in hot water compared to cold or lukewarm waters. Hot water also tends to open pores which increase your susceptibility to skin infections. A poorly maintained hot tub or swimming pool can cause common ailments such as urinary tract infections and rashes. This is why you should always use only the top hot tub chemicals.

Hot tub chemicals are a very important part of maintaining your hot tubs. Make sure you first read the manual and strictly follow it, especially on the proper use of these compounds.

Links, prices and images fetched from Amazon PA API. Last updated on 2020-04-02.

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