Umm, I dont know if the brita filter will adjust the PH, my water tastes the same and its PH is really high around (7.5-8.0) I would get a cheap Ph test kit for pools, maybe $10, and test the water before you water them, if its high, use a lemon or lime to bring it down until the tester reads out good. PH needs to be in the right range, if its to high (9.0+) they could die or stop growing same with too low (5.0-) (5.8-6.2 is ideal)