Catch rain water, I have 1 gallon jugs (about 20 of them) and I just fill them up when it rains. PH is always 6.5 and you can't beat mother nature. As far as tap water goes, just let it sit out overnight to evaporate the chlorine. Trying to boil it will just be a pain in the ass and the output wouldn't be worth it.
Just my take.