The key is your responsibility during your stay and if it is lost, I will have to charge you $75 for replacement.13.Please do not use bath towels for the pool as the chlorine damages the bath towels.  

Then we tried to kill the bacteria, which made the chlorine too high.  

Chlorine Bleach kills mold and mildew.

Same goes for chlorine, some supplies are highly chlorinated which eats rubber seals, but that can be fixed with a carbon filter.  

@Masa Asao   one of those in tank chlorine tablets might help.   

If you look at all the specialized products, they all contain a halogen derivative to kill mold - look at a periodice table of the elements and the second column from the right contains all the "-ine" compounds, chlorine, fluorine, astatine, etc.

Not only for the environment, but also the roof.Tide is a detergent and the active ingredient that addresses the roof is chlorine bleach.

They do release polluting gases they are not supposed to(chlorine, methane).

Chlorine bleach is a whole different story.  

Chlorine dioxide.