What Chemicals are Needed for a Hot Tub?

This content was previously featured on the Hot Tub Works website. Leslie's is proud to partner with Hot Tub Works to bring you this helpful content on lesliespool.com.


Spa chemistry is something that needn't make you anxious, and once you get the hang of it, most hot tubs will exhibit something of it's own chemical personality, one that you will get to know well.

What I mean is, you will get to know when it needs more of something, and if you were to really geek out, and keep a spa chemical log, (like me!), you can see water balance trends over time.

For instance, my hot tub is tested 2-3 times per week, and I record my readings in a little book. If I flip back thru, I can see that about every 3 weeks I lower the pH, and about every 6 weeks I need to raise the alkalinity. I also see that on average, I use about 14 bromine tablets and 9 oz of spa shock every month. Good to know.


But you didn't come here to hear stories about my hot tub - you came here to find out exactly what chemicals are needed to maintain a hot tub? What do you need to buy? And, what do you Really Need, and what is more... Optional.

There are a half-a-dozen different categories of hot tub chemicals, each with about a half-a-dozen different chemicals, from about a half-a-dozen different brands. And that's what makes hot tub chemicals seem so confusing; let's see if we can't Break it Down into smaller chunks...


  • Test Strips or Test Kit - test spa water 2-3x per week
  • Bromine tablets - for continuous sanitation
  • Bromine Booster - Raises bromide levels after draining
  • Spa Shock - regular super-sanitation, weekly
  • Spa pH & Alkalinity Balancers - as needed


  • Spa Calcium Increaser - increases water hardness
  • Hot Tub Clarifiers - coagulates small particles for easier filtering
  • Spa Cartridge Cleaner - get a second year with a deep cleaning
  • Mineral Purifier - purifies with copper and silver ions
  • Spa Polish / Spa Cleaner - clean and polish the spa shell


  • Defoamer - for foamy spa water
  • Metal Remover - or metal stain removers
  • Spa Cover Cleaner - and conditioner
  • Jet Clean - biofilm cleaners
  • Leak Seal - seals up weeps, seeps, leaks

A simple and more economical way to stock up on the basic spa care chemicals is to buy one of our 6 month spa care kits. We have 8 different spa chemical kits available from mild to wild, in your choice of bromine, chlorine or Nature2 mineral sanitation.

As a bare minimum, you have to have chemicals to test and balance the pH, continuously sanitize the water, and regularly oxidize (shock) the spa. An ozonator or mineral purifier by itself can't do the job alone; in addition, put bromine tablets into a spa floater, and then add a few capfuls of spa shock after using the spa.

Also important is to test and maintain the pH and Alkalinity, so it doesn't get too high or too low. Use test strips to test the water, and then add a pH or alkalinity increaser or decreaser, if pH has strayed outside of 7.4-7.6, or alkalinity is below or above the range of 80-120 ppm.

Happy Hot Tubbin'

Daniel Lara
Hot Tub Works