pH and Alkalinity

Ideal range: 7.2 - 7.6

Even the smallest change to your hot tub water can dramatically change your pH level:

The lower your pH, the more acidic your water is (sort of like lemon juice). The higher your pH, the more basic it is (sort of like soapy water). Many things can change your pH, such as:

The atmosphere
Occupants of the hot tub
Leaves, dirt and debris
Chemicals

Alkalinity

Alkalinity is a pH buffer, so you should keep it at between 125 ppm and 150 ppm. As a general rule, when your alkalinity is low, so is your pH.

If both levels are low, adding alkalinity can bring both back up to respectable levels. Or, you could always use pH increaser. When both your pH and alkalinity are too high, you can add pH decreaser and that will reduce both.

It’s important to keep your water balanced. Why? Acidic water will deteriorate your hot tub shell, plumbing and metal components – even the heating element. Basic water leaves behind a chalky residue, while unbalanced water can really damage your hot tub. To prevent costly replacement of parts, make sure you check your pH and alkalinity often.

Increase pH with pH Increaser

Decrease pH with pH Decreaser

Increase Alkalinity with Alkalinity Increaser

Decrease Alkalinity with pH Decreaser

CALCIUM HARDNESS

Soft water can really do a number on your shell and plumbing. When you have low calcium, your hot tub will try to get this anywhere it can, including the shell and plumbing. On the other hand, if you have too much calcium, scale will form on your heating element. This causes your heater to have to work overtime, which wastes energy.

Keep your calcium between 100 and 200 ppms. During startup, you may have to add calcium, and after that it should stay constant.

WATER TESTING

Test your water weekly, or daily if you use it every day. Keep many test strips handy. You’ll want the ones that check for chlorine/bromine, pH, alkalinity, and calcium hardness. If you have trouble finding hot tub-specific strips, use ones designed for pools.

For the most accurate test, follow these instructions:

Turn off the pump
Grab a plastic cup and reach into the middle of the tub. Flip the cup upside down, dunking it in the water up to your elbows. Turn it right side up to get a sample.
Quickly dip a test strip into and out of your sample.
Wait 20 second seconds, then look at the colored tabs on the strip and compare it with the color chart from the bottle.
Note the readings, adding the proper amount of chemicals to make adjustments.

BROMINE

Bromine is a sanitizer, preferred by some over chlorine because it doesn’t have an odor.

Bromine and chlorine are both in the same family, but bromine doesn’t kill bacteria as well as chlorine. Keep your bromine level between four and 6 ppms. In the end, your chlorine and pH levels are the most important levels to keep an eye on.