In Thailand some pool owners use salt, like half the salinity of the sea (the sea water combat most bugs, also algaeas to a certain degree, the ph must be right, can be adjusted by borax and citric acid
) A little H2O2 (Hydrogen-Peroxid)
can be used too.
-then the use of chlorine is down to a minimum, some dont use it at all. Never got sick of it, and the kids could play for hours without getting stingy eyes. And me not getting the dry chlorine skin.