I use tap water all day and night and its fine... My Tap is 7.5/250.. So I drop my PH and just take 250 off my number... Right now I have 2 in the 600-750 range (350-500) that are doing just fine. If you have o ppm water... you have to ADD everthing... so hard water has some good stuff to start.. and yes plants do need cholrine.
EDIT.. I now flush once a week for 24hours, seem to work very well. I do that with store bought bottleed water @ 6.0-005 24 hours of clean pure water... I like it,