Understanding Spa and Hot Water Chemistry

OK, so you bought a spa to relax, reduce stress, relieve tension and to get away from the fast-paced world around you. You've used it a couple times, and have found that it really is all those things and more. As a matter of fact, you don't know how you lived without it. It's great! But it is on this occasion when you lift the cover to get in, that it is no longer the sparkling clear water you are used to, but a cloudy and smelly mess.


What happened? The pump and filter seem to be working, the water is warm, and except for the way it looks and smells, everything seems to be OK. You find the owners manual and notice it recommends that you test your water. You see words and numbers like PPM (parts per million), sanitizers, total alkalinity, pH, and something about the possibility of the water being hard. This stuff would scare anybody. You panic! You don't know what to do.


So, you get the picture. Although this is a typical scenario, water chemistry doesn't have to be scary or difficult to understand.

The first thing that you need know is that your spa is not a tiny pool. Spa water - its treatment and parameters - is much different than a swimming pool . The main difference of course, is the temperature - spa water is most often set between 102 and 104 degrees Fahrenheit, while a pool stands typically at 82 degrees, which also means that there's far more opportunity for bacteria growth in a spa. Plus hot water opens pores, making bathers much more susceptible to skin infections. When not properly cared for, spa water can be responsible for common ailments like rashes and urinary tract infections. It can also cause cloudy water and damage the spa surface and equipment.   The previous paragraph was not intended to scare you, but to educate and stress the importance of testing the water and keeping it balanced. So, to help you get a handle on what water balance means, and how you can maintain it, let's look, one at a time, at the factors that shape your water quality.