You still have to add chlorine occasionally and I find it fussy.

The wrong chemistry, well, see what happens if you put a few drops of brake fluid into dry pool chlorine (actually, do not do this!).

I am going to test the chlorine levels in the water this Friday, but the tenant has asked about a whole-house water filter to reduce the chlorine levels. 

You can try a Chlorine Dioxide treatment.

And they have to be checked regularly for chlorine and pH level. 

Chlorine will KILL YOU .   

What happens is chlorine burns off and other chemical levels go lopsided in the hot months. 

Tile is among the least inhospitable surfaces to multiple drug-resistant organisms/superbugs, and if you work in a hospital or a nursing home, you've seen people die of superbug secondary infections, and you don't want to bring them home to your kids.Medical professionals also tend to put a lot of faith in chlorine bleach.

It's a real pita to keep it clean, check the chlorine and adjust, check the ph and adjust, add water when necessary, clean the filter, vacuum the inside, remove dead bugs and leaves, and this is only 20 feet from my back door. 

Someone mention it could be iron bacteria, and to try lemon or chlorine.