9 Best Hot Tub Chemicals of 2021 Compared & Reviewed

Best Hot Tub Chemical
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Like swimming pools, hot tubs require proper cleaning and maintenance, and part of this process requires various hot tub chemicals.

These not only create a safe and healthy environment to soak in but also help to soften the water, as well as balance the pH levels, resulting in reduced corrosion along the filtration, heating and circulation lines, odor elimination and reduced calcium build up.

Seeing that there are a lot of things that these products do, you need to get the best hot tub chemical for the job, and this review covers 10 of the best ones from which you can choose the one that will treat and condition your water accordingly.

What To Check Before Buying Best Hot Tub Chemical?

How to Buy the Best Hot Tub Chemical
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1. Types of Hot Tub Chemical

When selecting a hot tub chemical for your pool, there are a few types available to consider, and these are designed to perform different functions. They include:


Sanitizers are designed to clean and disinfect your tub by killing bacteria and other harmful microorganisms. These usually develop and grow very quickly in the warm tub waters and if not checked, might make you contact disease or infections as you soak in the warm water.

That said, the two most common sanitizers are chlorine and bromine, with chlorine being the cheaper and fast-dissolving, fast-acting option, but is dusty, has a strong odor and can cause skin and eye irritation.

On the other hand, bromine sanitizers are more expensive and dissolve slowly because of having a tablet structure, but they are better for warm water and are gentler on the skin. Chlorine is better suited for swimming pools, but it can also be used in hot tubs.

As for the optimum levels, it is recommended to maintain the sanitizer level at 1-5 PPM so as to effectively keep the water free from germs.

There are other oxygen, enzyme, and silver-based sanitizers, but these serve only to clear cloudiness in the water, but not for disinfection.

Sodium Bisulfate

This is the technical term or chemical name for what is popularly known as a pH and alkalinity lowering treatment. If the water pH is too high, you might experience scale build up on the pool’s equipment, which means water circulation, heating and filtration will not be optimal.

Therefore, if you experience such, consider getting a pH decreaser to balance out your water.

Sodium Bicarbonate 

Sodium Bicarbonate, also known as a pH increaser, raises the alkalinity level so as to reduce corrosion, reduce irritation, and create a conducive environment for the sanitizer to work effectively.

Basically, it is used for water balancing just like with Sodium Bisulfate, but in the opposite way.

Shock Treatments

Basically, shocking is an oxidizing treatment that breaks down and removes contaminants in the water, and it is necessary every once in a while, say weekly, because it helps get rid of the contaminants that your sanitizer has missed.

There are oxygen-based and chlorine-based shock treatments, with the former being gentler to the skin and the latter usually doubles up as a sanitizer due to the chlorine content.

Buying Guide: Sanitizers and shock treatments are absolutely necessary and should be used more often in your hot tub. Regular testing is also required so as to determine if you need Sodium Bicarbonate or Sodium Bisulfate for water balancing.

2. Compatibility

Since you will most likely use more than one chemical to clean your hot tub, it is important to look at the compatibility factor of each so that the mixture you use does not cancel out the effect of each other and lead to no sanitization or water balancing.

3. Safety

Safety is also very important to consider because your health should be your most primary concern. Before soaking in and risking your skin to harmful side effects, ensure that the chemical is user-friendly and safe to use.

The most usual case is skin irritation, which results from the acidic side effects caused by chlorine-based sanitizers. If your skin is very sensitive, then it would be wise to go for the non-chlorine-based chemicals.

4. Ease of Use

Each hot tub chemical has its own recommended way of use, and this should be strictly followed for proper water maintenance.

There are those that simply require to be dropped in the water directly because they are in a granular form that dissolves very quickly (mostly chlorine-based sanitizers).

Others, however, require floating feeders to dispense and although this is not a complex application process, it is definitely not as easy as simply pouring out the chemical to the tub.

NB: whichever chemical you buy, always ensure you apply it in the recommended dosage and test continuously thereafter to ensure it is at the correct level.  

5. Speed

When it comes to speed, this refers to the amount of time it takes for the chemical to take effect. It is mostly determined by the size of the chemical particles, in which granules are fast dissolving and their cleaning/sanitization effect is almost instant.

On the other hand, tablets take a longer time to dissolve and might require you to wait for some time before soaking into the tub.

9 Best Hot Tub Chemicals of 2021 Reviewed




Leisure Time Spa Up 30410A - 22339A Spa Balance

1. Leisure Time Spa Up 30410A – 22339A (Cheapest)

  • Affordable
  • Compatible with all kinds of sanitizers
  • Raises the pH and total alkalinity
Leisure Time 30330A Spa Sanitizer

2. Leisure Time 30330A (Best Spa Chemical)

  • Fast dissolving chlorine granules
  • Sanitizes water, but can also be used for shocking
  • No effect on water balance
SpaGuard Enhanced Shock

3. SpaGuard Enhanced Shock (Best to Use)

  • Shocks in as little as 15 minutes
  • Clarifies and gets rid of bad odors
  • Compatible with chlorine and bromine spas
SpaChoice 472-3-5081 Chlorine Granules

4. SpaChoice 472-3-5081 (Best Sanitizer for Big Hot Tubs)

  • Large 5-pound quantity
  • Fast dissolving chlorine granules
  • UV stabilized for increased chlorine lifespan even in outdoor hot tubs
Oxy-Spa Non-chlorine Hot Tub & Pool Shock

5. Oxy-Spa Non-chlorine Hot Tub & Pool Shock (Best Natural)

  • Oxidizing shock with high levels of active oxygen
  • Fast dissolving with very quick results
  • Generous dosage of 1.5-2 ounces/500 gallons
Spa Choice Hot Tub Chemical Balance Pack

6. Spa Choice Hot Tub Chemical Balance Pack (Best for Sensitive Skin)

  • pH increaser and alkalinity up prevent corrosion
  • pH decreaser prevents scale build up
  • Calcium increase reduces foaming
Leisure Time RENU2 Spa Shock Renew

7. Leisure Time RENU2 (Good)

  • Chlorine-free
  • Eliminates cloudiness, odor, and contaminants
  • Does not affect pH level
Spa Essentials 32130000 Chlorinating Concentrate Granules

8. Spa Essentials 32130000 (Concentrated)

  • Highly concentrated chlorine sanitizer
  • Also acts as an oxidizer
  • UV stabilized
  • No pre-dissolving required
Leisure Time Spa Disinfectant 45430A Brominating Tablets

9. Leisure Time Spa Disinfectant 45430A (Low Dust)

  • Low dust, low odor brominating tablets
  • Large 4-pound quantity of tablets
  • Based on Dantabrom chemistry, with 10% more active sanitizer

1. Leisure Time Spa Up 30410A – 22339A – Cheapest

Leisure Time Spa Up 30410A - 22339A Spa Balance
Photo: Leisure Time

If you are on a tight budget, you can still get this Spa Up from Leisure Time. However, the product does not sanitize or disinfect the water, rather it just raises the pH level and total alkalinity so as to increase the effectiveness of the sanitizer.

This is quite important though as a pH level lower than 7.2 can cause corrosion on the attached equipment. Properly balanced water should have its pH maintained between 7.2 and 7.8.

The proper application method, therefore, means that it should be used together with other hot tub chemicals, specifically sanitizers, and can only be applied if the water balance has been affected.

On the bright side, the spa balance is compatible with all kinds of sanitizers (bromine, chlorine, and biguanide), and dissolves very quickly in water due to its granular structure.


  • Affordable
  • Raises the pH level and total alkalinity
  • Compatible with all kinds of sanitizers
  • Fast dissolving granular structure


  • Does not sanitize

2. Leisure Time 30330A – Best Spa Chemical

Leisure Time 30330A Spa Sanitizer
Photo: Leisure Time

This sanitizer is a very good spa chemical because it is packed as small chlorine granules that dissolve very quickly so as to maintain clear, clean and sanitized water in the shortest time possible.

Apart from sanitization, the 30330A can also be used to shock your hot tub, and in all these functions, it does not upset the water balance and is almost pH neutral.

However, for the product to work as described, it must be applied in certain ratios, which are 0.5 ounces/500 gallons of water for normal sanitization, and 1 ounce/500 gallons for shock treatment.

Coming in a 2-pound (32-ounce) bottle, this gives you a lot of chemical for long term hot tub treatment.

The product is also stabilized against UV radiation, which means it can be used in outdoor pools, providing a steady chlorine source that kills bacteria and controls algae growth. However, the chlorine might not be ideal for people with sensitive skin.


  • Small chlorine granules dissolve quickly in water
  • Can be used as a sanitizer as well as for shocking purposes
  • Does not upset the water balance
  • Packed in a 2-pound bottle that can be used for a long time
  • Stabilized against UV radiation


  • Not ideal for people with sensitive skin

3. SpaGuard Enhanced Shock – Best to Use

SpaGuard Enhanced Shock
Photo: SpaGuard

For a hot tub chemical, this one from SpaGuard stands out from the rest since it is an enhanced shock the performs 4 functions. First, obviously is shocking, in which it dissolves and works quickly so that you can soak inside in as little as 15 minutes.

The chemical also clarifies water so as to restore your spa’s sparkle, acts as a flocculent and lastly, is a pH buffer that prevents any effect on the water balance. Combined, these make it the top-rated hot tub chemical in this review.

Other than this, the enhanced shock also gets rid of unpleasant odors and is compatible with chlorine and bromine spas, or even those utilizing ozone or ionization systems. More features include a 2-pound container, which packs a 58.2% Sodium Dichloro-s-Triazinetrione powder.


  • Shocks and dissolves in as little as 15 minutes
  • Clarifies water
  • Acts as a flocculent
  • Does not affect the pH level
  • Compatible with chlorine and bromine spas


  • Might cause irritation to people with sensitive skin
  • Not stabilized

4. SpaChoice 472-3-5081 – Best Sanitizer

SpaChoice 472-3-5081 Chlorine Granules
Photo: SpaChoice

Though very costly, the 472-3-5081 SpaChoice chlorine granules come is a 5-pound container, giving you 80 ounces of hot tub chemical sanitizer, which is quite a lot. This can be used on big tubs on multiple occasions before requiring a replacement.

Since they are in granular form, the chemical dissolves very quickly when dropped in, and sanitizes your tub in a very short time by killing bacteria, controlling algae, destroying organic contaminants and eliminating bad odor.

The only problem is that the resulting water composition might be a little bit irritating to people with sensitive skin, but the available chlorine is only at 56%, which means it is not very highly concentrated and the irritation will only be mild.

Another desirable feature of this product is that the chlorine granules are UV stabilized, which increases the life of the chlorine element even if used in outdoor spas.


  • Large 5-pound quantity
  • Fast dissolving chlorine granules
  • Eliminates bad odor
  • UV stabilized for extended chlorine sanitization


  • Costly
  • Might cause mild skin irritation

5. Oxy-Spa Non-chlorine Hot Tub & Pool Shock – Best Natural

Oxy-Spa Non-chlorine Hot Tub & Pool Shock
Photo: Oxy-Spa

Fresh natural water is usually free of contaminants and full of oxygen and thus, a natural hot tub chemical should restore your tub’s water to this state.

Oxy-Spa’s non-chlorine hot tub shock does exactly this with its granular oxidizing shock, which has the highest level of active oxygen, going up to 4.3%.

Though the product does not have disinfecting properties due to a lack of chlorine, the granules do not cause any skin or eye irritation once dissolved in water and are fast dissolving, in which you can use your tub immediately after application as the shock acts instantly.

The actual shocking treatment eliminates soaps, natural oils, lotion and build-up in your tub, while also quickly breaking down contaminants such as cosmetic residue, perspiration and the like, leaving the water crystal clear, clean and fresh.   

This is then topped off by the oxidation process as well as odor elimination, which combined, leave your tub having fresh natural water in a very short time.

Other features include a generous dosage of 1.5-2 ounces/500 gallons of water, and considering that you get two 1.5-pound bottles, a total of 3 pounds will help you maintain your tub for a while.  


  • Contains high levels of active oxygen
  • Non-chlorine, with reduced skin and eye irritation
  • Fast dissolving granular structure
  • Shocks and removes any cloudiness quickly, allowing you to use the tub immediately after application
  • Generous dosage of 1.5-2 ounces/500 gallons of water


  • Does not disinfect

6. Spa Choice Hot Tub Chemical Balance Pack – Best for Sensitive Skin

Spa Choice Hot Tub Chemical Balance Pack
Photo: Spa Choice

If you have sensitive skin, this kit is the best option because it contains different chemicals that help maintain water balance for comfortable use.

Coming in a pack of 4, the first chemical is a 16-ounce pH increaser, which is used to raise low pH levels so as to prevent corrosion on the attached equipment, optimize the sanitizer’s effectiveness and reduce skin and eye irritation.

A 16-ounce alkalinity-up is also included for raising low alkalinity so as to prevent corrosion while a 24-ounce pH decreaser counters these effects by lowering high pH and total alkalinity in case it is too high, preventing scale build up.

The last item is a 14-ounce calcium increase, which raises calcium hardness so as to prevent corrosion and reduce foaming.

This results in balanced water that is gentler on the skin and allows any sanitizer that you use to work more effectively.


  • pH increaser prevents corrosion, optimizes the sanitizer’s effectiveness and reduces skin-eye irritation
  • Alkalinity up prevents corrosion
  • pH decreaser prevents scale build up
  • Calcium increase prevents corrosion and reduces foaming


  • Sanitizer not included
  • Does not disinfect

7. Leisure Time RENU2 – Good Hot Tub Chemical

Leisure Time RENU2 Spa Shock Renew
Photo: Leisure Time

Leisure Time’s Renu2 is also a quick dissolving hot tub chemical, but it is chlorine-free and acts as a shock oxidizer that gets rid of cloudiness in the water, bad odor, and contaminants such as soap and oils. However, it does not disinfect the water.

That said, the product comes in a 2.2-pound (35.2-ounce) container that packs enough chemical for long term treatment.

This is because it should be used in the ratio of 2 ounces/250 gallons of water for shock oxidization, and 4 ounces/250 gallons when used as part of the reserve-and-renew sanitizing system.

However, you should be careful not to use it as part of Leisure Time’s Free System as the chemical is not compatible.

The chlorine-free granules though are compatible with chlorine, bromine, and mineral purification systems, and are buffered so as to prevent pH fluctuations while preventing chloramine build up at the same time.


  • Chlorine-free (does not cause skin irritation)
  • Gets rid of cloudiness, bad odor, and contaminants
  • Compatible with chlorine, bromine, and mineral purification systems
  • Does not affect the pH level
  • Prevents chloramine build-up


  • Does not disinfect water
  • Not compatible with Leisure Time’s Free System

8. Spa Essentials 32130000 – Best Concentrated

Spa Essentials 32130000 Chlorinating Concentrate Granules
Photo: Spa Essentials

This chlorinating concentrate is basically a granular sanitizer that is quick dissolving and has a high concentration of Sodium dichloro-s-triazinetrione, going up to 97%.

Though this might be slightly irritating to people with sensitive skin, the result is a fast-acting formula that will kill and control bacteria in a very short time.

The sanitizer actually also acts as an oxidizer and therefore, there’s no need to buy the two products separately.

Other features include UV stabilization, which means the granules can be used in outdoor pools and still give extended protection, a relatively large quantity 2-pound container, and the chemical can be added directly to the pool or spa with no pre-dissolving required.


  • Quick dissolving granular sanitizer
  • Highly concentrated, with 97% Sodium dichloro-s-triazinetrione
  • Also acts as an oxidizer
  • Stabilized against UV radiation
  • No pre-dissolving required


  • Might cause skin and eye irritation

9. Leisure Time Spa Disinfectant 45430A – Low Dust

Leisure Time Spa Disinfectant 45430A Brominating Tablets
Photo: Leisure Time

Coming in a large 4-pound container, these 45430A brominating tablets are characterized by being low-dust, low-odor hot tub chemicals because, as the name suggests, they are in tablet form and not powder form, which is the case in most chlorine sanitizers.

However, this means that they dissolve slowly in water, and require spa floaters for dispensation. On the plus side, the tablets fit easily in most floating feeders, which means you have the option of buying any floater of your choice.

The tablets are also based on Dantabrom chemistry, which provides 10% more sanitization power, resulting in cleaner, healthier and safer water to soak in.

With a recommended dosage of 0.5 ounces/100 gallons of water, the 4-pound quantity will surely serve you for a long time


  • Large quantity
  • Low-dust, low-odor tablets
  • Based on Dantabrom chemistry, providing 10% more sanitizing power
  • Tablets easily fit in most floating feeders


  • Slow dissolving
  • Requires a floater for dispensation


Hot Tub Chemical Myths

1. Chlorine pool chemicals are cheaper to use

Most chlorine tablets might seem as versatile enough to be used in both swimming pools and hot tubs, but they are made for the cold pool water and thus, are not compatible with hot tub water. They might overreact, causing the water to be imbalanced.

Though it is a cheaper method, the end result is not ideal and might make you spend much more in trying to maintain water balance.

2. Chlorine causes irritation

Technically, chlorine does not cause irritation to the skin or eyes. Rather, people with an allergy to chlorine and have sensitive skin are the ones who will be affected.

What chlorine does is to lower the pH level, which makes the water slightly acidic, and this is what causes the irritation.

3. Chlorine/bromine tabs are completely safe to use

Even though chlorine and bromine tablets are very commonly used as hot tub sanitizers, their high concentration might damage some parts of the tub, especially if you have a small one. This is because the volume of water is very little, which might lead to dangerously high PPM values.

4. Shocking needs to be done every week

Even though tub shocking is recommended to be done every week, this is the ideal maintenance schedule that is required if you regularly use your hot tub. If you rarely use it, then it would be pointless and wasteful to adhere to this timeline.

You can even shock the water just a single day before use, then forget the entire process until the next time you want to use the tub.


Out of the list above, all chemicals can be considered very useful if you own a hot tub because not all of them have the same functionality. Some are sanitizers, others pH increasers or decreasers, and the rest are meant for tub shocking.

Ideally, you should have at least a set of all these 4 types, which should be compatible with each other, so that you can utilize all of them as the best hot tub chemicals for proper maintenance of your tub and perfect water balancing.