Chemicals you Need to Balance your Hot Tub Water

Keeping a clean and healthy hot tub means taking good care of its water so you can get the most out of your hot tub experience. After you clean out your filters and fill your hot tub with water, which you find how to do in the Using your Hot Tub in the Fall article, it is important to keep your PH and alkaline levels balanced. Visit our services page or our service center for more information about what we can offer. Here are the test strips and chemicals you should always have for your hot tub water along with the 5 steps to take to balance and sanitize your water:

What you Need:

  • Calcium hardness, PH level, total alkaline, chlorine/bromine testing strips. (You can also come into one of our store locations for free water testing!)
  • Calcium hardness increaser.
  • PH increaser and decreaser.
  • Total alkalinity increaser and decreaser.
  • Chlorine or bromine.
  • Shock oxidizer.
  • Other chemicals such as minerals, defoamer, and spa clarifier.

Step 1: Calcium Hardness

This refers to the total amount of calcium and magnesium dissolved in your water. This shows the softness and hardness levels. Use a calcium hardness test strip to see if you will need to increase or decrease the calcium levels of your water. Your levels should range between 150-250 ppm on the testing chart. You should test your levels about two times a week. Refer to your hot tub’s owner’s manual to find how much calcium to add to the water.

If your calcium level is too low, below 150 ppm, this will cause erosion and therefore can damage your hot tub. Use a calcium increaser.

Step 2: PH and Alkaline Levels

The PH and total alkalinity levels work together to control and stabilize your water. The total alkaline measures the alkalinity, which controls the PH levels. The PH controls the acidity in your water. You first need to stabilize the alkaline levels before addressing the PH levels. The ideal range for total alkalinity is between 80-120 ppm. The ideal range for PH is between 7.4-7.6. You can test your water from time to time, ideally about once or twice a week. Read your hot tub’s owner’s manual to know how much to add to your water.

  • If you need to increase total alkalinity, add an increaser.
  • If you need to decrease total alkalinity, add a decreaser.

Too high of a PH level, above 7.6, will cause stains to appear on the side of your hot tub and the water will become cloudy. Too low of a PH level, below 7.4, can cause damage to your filters, be uncomfortable to soak in, and even cause skin irritation.

  • If you need to increase the PH level, add an increaser.
  • If you need to decrease the PH level, add a decreaser.

For more information about PH and Alkaline levels and how often to check, read our article about hot tub maintenance.

Step 3: Sanitize your Hot Tub

There are two main sanitizers you can use for your hot tub’s water. They are bromine and chlorine. You should sanitize your hot tub weekly. They both have their own pros and cons:


  • Pros: has more resistance and lasts longer, holds up better in heat, is reactive with a small amount of chlorine and MPS shock, more effective over time, less smelly than chlorine.
  • Cons: is a bit more expensive, burns off quicker in the hot sun, takes longer to sanitize than chlorine so may need to wait longer.


  • Pros: highly effective at killing algae and other unwanted bacteria, easy to manage, is cheaper.
  • Cons: smelly when oxidized with contaminants, can cause irritation to sensitive skin.

Refer to your hot tub’s owner’s manual to know how much to add to your water.

Step 4: Spa Shock

You can use a non-chlorine shock. If your water is cloudy and unpleasant, you can add some shock to break down that waste and clear your water. You should shock your hot tub water about once a week to keep it looking and feeling great. The purpose of shock is to essentially keep the nasty germs at bay and allow your sanitizers like chlorine and bromine to work more effectively. Shock kills germs and frees up the available chlorine or bromine in your water. You can refer to your hot tub’s owner’s manual or the shock package for how much to add.

Step 5: Other Chemicals you can Use

Additionally, you can add other chemicals to your hot tub as you feel necessary.

Minerals are another form of sanitizer you can use. By using minerals, you can use less chlorine, which is especially useful if you have a sensitivity to chlorine. Minerals are easy to manage and can combat some of the cons of chlorine such as the smell.

Having friends over and need something to quickly clean up the foam forming around your hot tub? You can use a spa defoamer to clean that up in a jiff.

Sometimes, it is nice to have a spa clarifier on hand if your water is looking a little foggy. It is is sign you may need to clean your filters, but using a clarifier is a quick and easy cleanup when you need it.

For more help, you can visit our service page or come by our service center in Portland, Oregon.

Have any other questions about hot tubs or Spa Logic? Check out our Frequently Asked Questions page to help find answers fast.


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