A Guide to the Best Hot Tub Chemicals

Answering the question, “Which hot tub chemicals are best?” can be somewhat tricky. The answer, of course, is to go with the chemicals that best serve the make and model of your hot tub, as well as how much you want to invest in its initial setup. By following this guide, we will help you save lots of money (and hours of frustration).

First you’ll need to choose a hot tub sanitizer — bromine or chlorine. A bromine-based sanitizer may carry a higher upfront cost than chlorine, but comes with many benefits that can pay off over time. You must also consider the location (indoors or outdoors), as well as how often you plan on using your hot tub.

Sounds like a whole lot to take in right? But, don’t worry; this blog post will help you get a better grasp of all those sanitizers, shock products, and pH balancers that are on the market.

Read on to find out which hot tub chemicals are best, based on your desired usage and water quality.

Step 1: Balancing Your Hot Tub’s Alkalinity, pH Level, and “Hardness”

Many new hot tub owners throw in all the chemicals they have in their kit and hope for the best. This is a mistake that can lead to hours of frustration. Your hot tub chemicals can interact in ways you would not expect. By not balancing your hot tub from the start, you will reduce the effectiveness of sanitizing agents, shock treatments, and clarifying products later on.

The first step of balancing your hot tub’s water is crucial. To do this, you will need to use test strips that will indicate the water’s:

  • Total alkalinity
  • Calcium level (water hardness)
  • pH level

Your hot tub’s total alkalinity should fall somewhere between 80-120 ppm. Comparing your strip’s color to that on the container should indicate whether your water’s alkalinity is too high or too low. If the alkalinity is too low, you can use a total alkalinity-increasing product; too high, you should look at a calcium filter or products to control the level of calcium in the water.

Now, onto the pH level of your hot tub; ideally, your hot tub’s water pH level should be in the range of 7.4-7.6. But, any level between 7.2-7.8 is largely seen as an acceptable amount. We would be happy to recommend the right product to balance your hot tub’s pH level.

Step 2: Choosing Sanitizers

Every time you use your hot tub, you should run a test beforehand to make sure the water is safe.

When it comes to sanitizing your hot tub, you essentially have two options: chlorine or bromine. While these two are chemically alike, those similarities disappear once hot water is thrown into the mix. So what are the differences between the two?

  • Chlorine — Chlorine is essentially a fast-acting sanitizer and decontaminating agent; it goes in, kills off the germs and bacteria and then is basically spent in just a few hours. Once chlorine is heated up, it forms chloramine —gas that slightly irritates your eyes and nose. One good thing about chlorine is that you can test the water, add the desired amount of chlorine, and retest a short time later to reach the perfect concentration.


  • Bromine — If you choose bromine as your sanitizer, you will want to build up a reserve of bromine in your hot tub’s water. This takes a bit of patience, but can easily be achieved by first adding sodium bromide along with a shock oxidizer when you first fill up your hot tub. After this, wait a while, then try to achieve a bromine level of 10 ppm. But, you will want to wait until your hot tub’s bromine levels settle down to 4-6 ppm before using your hot tub. With bromine, you will still need to shock your hot tub on a weekly basis to take care of any remaining organic contaminants. Which brings us to Step 3: finding the right shock treatment.

Step 3: Shock Treatments

Whether using chlorine or bromine as your sanitizer, you will need to shock your hot tub at least every week. The best time to shock your hot tub is right after you use it; shocking your hot tub directly before use can irritate the skin, as well as reduce its effectiveness. Shock treatments help to dissolve residues, oxidize sanitizers, as well as remove chloramines or bromines.

  • Bromine “Shocks” — For bromine-based hot tubs, a non-chlorinated shock is recommended. But, remember to wait several days until your bromine levels settle to around 4 – 6 ppm before using your hot tub. With hot tubs that use bromine as a sanitizer, you are technically not “shocking” the water when adding non-chlorinated shock, but instead rejuvenating the bromine.


  • Chlorine Shocks — For chlorine-based hot tubs, calculate the amount of chlorine granules you’ll need to bring your chlorine level to around 10 ppm. Be sure your hot tub’s pH is balanced before adding the granules. Next, run the circulation pump on its highest setting to quickly disperse the shock treatment and keep the cover open for about half an hour. Once your chlorine levels drop back down to 5 ppm, your hot tub is safe to use.

Have Fun!

Thanks for reading our blog article! Hopefully it helped your understanding of the best hot tub chemicals for your particular goals. By keeping your hot tub balanced and sanitary, you will get much more use and enjoyment out of it, while also protecting all its various components. Stay safe and have fun!