I dont know If I can help, bute here is my opinion.
Most pools have water treated with Chlorine
and the most recent pools have no chemical treatement but the water is treated with Ultra Violet rays (or other kind of radiations), the last ones are more healty.
is bad to asthma
Another thing that asthmatics (like me), use to have asthma during intense exercise.
Hope you get better.
Sorry my english.