Hello Red20,

Chlorine dioxide is very volatile. At warmer temperatures it tries to escape. Depending upon what conditions are like where you are, you may only see a slight drop in concentration, or you can see a large drop in concentration.

In order to figure out how this applies to you, you need to run some tests.

Mix up a batch and test the concentration of chlorine dioxide. Let it sit for a day and test again. Let it sit for a week and test again.

On the other hand if you mix it up fresh each day you start with about the same concentration each day.

If you mix up a weeks worth, or a months worth, at one time, it will be more stable if you keep it refrigerated.

Tom