I'm not sure what the impact is, but I do know that it isn't beneficial too the plant. I had to email my water company to find out if they used chloramine, or chlorine. Like I said you can use it most people use tap for house plants, and they survive. The plant doesn't want it tho, so I won't give them it lol. There may be no noticeable difference in the plant at all. It's just 1 of those things that I can simply not give them so I won't. As for the pH down same thing. I plan on getting some organic pH down, but for now I try not to use it. Just got into organic growing so still learning more than I know hahaha.