Swimmers complain of sore eyes and a chlorine smell. They say there is too much chlorine but my test says my chlorine level is about right at 1.5ppm. What's wrong?

Ans.

There is probably not enough chlorine. Under normal circumstances chlorine breaks up organic material to harmless, un-noticed nitrogen and salts. But if the chlorine level is low or the organic material level is high the chlorine slows down its work rate and produces instead Nitrogen Trichloride. This is a type of tear gas, hence the sore eyes. The swimmers are not smelling chlorine they are smelling the Nitrogen Trichoride and mistaking it for chlorine.
 
The solution is to not let your chlorine level get to low and anticipate a raise in organic material level.
 
Stinging eyes can also be caused by the acidity level of your pool being to high, so always check this possibility too.

Back