Hot tubs are a great addition to your spa equipment. Most are inviting and clean, but if not well taken care of, they can harbor algae, nasty bacteria, and have a foul smell. You have to use various chemicals to keep the tub and the water clean and free from harmful organisms. To do so you should know which chemicals to use and when, to keep the water ready at all times.

Ensure you check the pH levels, calcium hardness, and alkalinity several times a week. You should also add balancers and other chemicals for Hot Tub Chemicals to keep the water clean.

Does this sound difficult? Don’t worry. You do not require a Ph.D. in chemistry to understand hot tub maintenance.

What chemicals should I use in my inflatable hot tub?


Your hot tub needs to be cleaned regularly to avoid a build-up. You should clean the filter cartridges, plumbing lines, the shell of the hot tub and the spa cover. As a general rule, you should never use household chemicals to clean the spa as it may result in foaming.

The filter catches grease, dirt, twigs, and other impurities. However, it should be cleaned regularly, otherwise it will end up clogging and potentially blocking the filter, which could lead to contamination and growth of algae.

Leisure Time A Bright and Clear Cleanser for Spas and Hot Tubs is one of the most used hot tub cleaners. It works by suspending contaminants and clumping them together so the filter can trap them. The cleanser is specially made for use in hot water and works well with most sanitizers.

For filter cleaning, Leisure Time- Jet Clean does a great job keeping your cartridges and plumbing free of grease and dirt.


If you notice your water looks cloudy and is not as sparkling as it should be, chances are your filter is not working well. If the filter works fine, you may be having water sanitation issues.

Some particles are too tiny to be picked up by the filter and they may find their way into your tub water, making it look cloudy and unappealing. For this reason, you’ll need to add clarifiers. Adding two cup-full will leave your water looking spring-clear.

Clarifiers are positively charged polymers. They attach themselves to negatively charged particles in the water and, in the end, form big clumps that can be easily trapped by the filter. Pay attention not to use too much as they may have the opposite effect of gumming up your filter.

Rendezvous Spa Clarifier will restore the water to sparkling again. The chemical in this clarifier rapidly digests oils, lotions, and organics to prevent waterline buildup, improve filtration, and avoid clogged filters.


Balanced spa water should have all chemicals at a balanced range. When the spa chemicals are imbalanced, parameters such as alkalinity and pH will be affected. Balancing chemicals are meant to balance the range of the spa chemicals, determined by a Saturation Index Calculator.

Total Alkalinity and pH

Alkalinity is the level of salts- carbonates and bicarbonates- which affects the balance of the water by acting as a buffer to stabilize the pH. pH is the acidity or the alkalinity of your water. The ideal pH ranges from 7.2-7.6. Anything above or below this is considered detrimental. A pH below 7.2 means your water is acidic, while higher than 7.6 means it’s alkaline.

Increasing and Decreasing

If the water is acidic, it can corrode and damage the tube’s inner parts, including the plumbing. On the other hand, alkalinity can lead to your water looking cloudy, scales, and stains. It can also indicate excess calcium in the water, which starts forming on the tub’s surface and in the pipes.

For these reasons, you need to increase or decrease the pH accordingly.

Of all balancing chemicals, a pH reducer is the most commonly used. This is usually because the alkalinity and pH of hot tub water tend to increase and a pH reducer decreases booth successfully.

  • If you need to lower the pH, use a spa pH reducer.
  • If you need to raise  the pH, use a spa pH increaser.

Total Hardness

This is the level of calcium salts in the water that affects the balance and determines how much scaling there is and how corrosive the water is. When the calcium levels are at peak, the water attains total calcium hardness. You’ll notice scales on the body shell of your hot tub, and the water will look cloudy.

If the water is too soft, the hardness level will be low, and it will be forced to draw from other minerals like iron, copper, and aluminum found in the parts making your tub. This could damage your tub.

To avoid this, make sure your hot tub calcium reading remains at 100-250PPM. If you notice low hardness, you can add calcium booster in the water.


We use sanitizers every day to kill germs, bacteria, and pathogens.

There are two main types:


Chlorine dissolves in water to form hypochlorous acid, which breaks down the bacteria and kills them. The hypochlorous acid reacts with other materials in the process and becomes deactivated, thus the need for constant treatment.

What you need to do is to add chlorine granules in the water and wait for them to dissolve. Chlorine is known for its stinky smell which causes eye irritation. For this reason you should never use chlorine tablets in a spa as they’re specially formulated for swimming pools.


People use Bromine tablets as sanitizers in the spa. The chemical works by ionizing the contaminants, breaking their chemical bonds. Unlike chlorine a sufficient amount of bromine can keep working for some time.

However, bromine also produces bromamines. These are not as destructive as chloramines, but they still reduce the working of bromine in your hot tub. Shocking is the only way to get rid of them.

  1. Chlorine kills bacteria more quickly than bromine.
  2. At high levels, chlorine can be harsh on your skin, eyes, and hair. It can also cause breathing problems when chloramines linger in the humid air in the spa. Bromine is gentler on the skin though it might be hard to wash off after being soaked in it for a long period of time.
  3. You should use 1-3 PPM of chlorine or 3-5PPM of bromine.
  4. Chlorine dissipates quickly, becoming ineffective; thus, you should replace it often while bromine takes time to dissipate and kill bacteria for longer periods.

Make sure you keep a sufficient level of sanitizer in your hot tub. If they fall below the required, pathogens, bacteria, algae, and other contaminants may grow even in a hot water or tightly closed tub.


Spa shock is also somewhat of a sanitizer. It is used to clear out any pathogens or contaminants that the other sanitizer missed.


  • To clean out chloramines and bromamines formed after chlorine and bromine have dissipated.
  • Used to activate bromide salts into bromine. If you are using bromine tablets, you don’t need to activate them.
  • Supplementing your daily sanitizer after a heavy use of spa (like a four-person soak).
  • Killing algae, removing water discoloration, restoring clarity, removing bad odors, and solving other water problems.

Chlorine and non-chlorine shocks (MPS) are the most common because they are fast dissolving and work well with both chlorine and non-chlorine sanitizers.

Make sure you test your water balance first using test strips from a test kit before shocking and adjust it accordingly. Follow the instructions on the label regarding the dosage depending on the amount of water in your hot tub.

Specialty Spa Chemicals

These are all the other chemicals people use in the spa that do not fit in all the other categories. They include algaecides that kill algae and prevent them from growing inside the tub; metal defenders to keep dissolved solids in solution; enzymes to digest natural oils.

Aromatherapy scents fall in the specialty products category. Though they are not a need, you can still add them. Also, there are scents explicitly made for the hot tubs.

Can you go in a hot tub without chemicals?

You can but it’s next to impossible to maintain a hot tub without the chemicals. Pathogens and bacteria will definitely enter in the water. You’ll also leave skin, lotions, and makeup whenever you soak. You require the chemicals to get rid of all these.

Alternatively, you can opt to drain and refill the water every two days which is not only expensive but also time-consuming.

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

Depending on the levels, you should wait for several hours to get in the tub. 6-8 hours are ideal but some chemicals like chlorine can take up to 24 hours. Use the hot tubs chemical testing kit to test for pH and chemical levels. For a shock treatment, it can be as little as 20 minutes unless you used a chlorine shock.

Are hot tub chemicals bad for you?

Hot tub chemicals make the water safe for use. However, they have their disadvantages. For instance, chlorine causes respiratory problems, skin problems as well as eye and throat irritation. Bromine poses some risks too.

While they may have a negative effect on your health, you can reduce the effects by shocking after each use, showering before and after use, using the minimum recommended amounts, cleaning the filter and tub before or at a recommended interval, checking and adjusting the pH level daily, and changing water before or at a recommended interval.


Owning a hot tub is more than just soaking in and relaxing after a long day. Of course, that is the primary reason to purchase a hot tub, but you need to take care of it and constantly treat the water to ensure maximum benefits.

Hot tub water chemistry may seem hard to understand, but it’s easy when you get used to it. You only need specific chemicals to keep the water balanced and keep contaminants out. Use a test kit with test strips to test the water first before attempting to add any chemicals. Correctly balanced water will not only be free of contaminants but also give you a perfect relaxing experience.