Pool allergy

The water temp makes a difference. The warmer the water the faster the stabilised chlorine breaks down and the greater effect it will have one you. Chlorine is naturally a gas at room temp and wants to return to this state.

Sometimes they use unstabilised chlorine as a shock treatment.but would need to clear the pool to use it. Large doses that turn to gas quickly but kill everything that you want killed.

Hence the normal stuff is stabilised chlorine. Chloruine bound to other stuff that breaks down slower. The warmer the pool the quicker it breaks down and therefore the more chloriney it is.

Sciencey enough for you?

I thought "UV filtration clever thingy" was pretty technical sounding, but looks poor compared to your explanation .

Interesting though .

m..eface- that makes sense-simming pools in hotter climates need their chlorine levels checked as the stuff evaporates in the sun so it does the same in warmer pools too. I would guess that unlike outdoor pools where evaporation takes the gas away from water level ,in indoor pools its more likely to sit just above water level or at a lower level generally where we are going to be exposed to it.So its not necessarily the variation of chemicals  but the gas concentrations thats the cause of irritation.

So I wonder what the regulations about this say ,as after all ,exposure to irritants in factories and places of work is strictly controlled