Hot Tub Water Chemistry

Sanitizers

Before we proceed, there are two terms that you should understand as you evaluate which sanitizer is right for you and how effective it is after you have used it:

• Sanitizer Demand The amount of any sanitizer product (in any form) needed to kill all the bacteria present in the body of water.
• Sanitizer Residual The amount of sanitizer (expressed in parts per million) that is left over after demand is satisfied.
• Sanitizer Availability Sanitizers will "combine" with other elements present in the water, meaning some will be "locked up" or "unavailable" for oxidizing bacteria while some will be "available" for that sanitizing purpose (expressed as the residual).

The purpose of any sanitizer is to kill bacteria in the water, which is done by oxidizing organic material in a process akin to rust on metals. The most common sanitizer is still chlorine, because it is readily affordable and available in a variety of forms. That said, alternatives are growing in popularity and will also be described here.