I asked this question earlier in the organics section but their is never a lot of people looking in there so I'll try it here. I wanted to bring down the ph of my tap water from 7.2 to 6.5. Being cheap and not wanting to use a lot of chemicals I read about using vinegar. I mixed it with the water and checked the ph until it was at 6.5. I then let it sit and checked it again. I watered the seedlings and the next morning they were all laying down and really mushy in the stalks. All 9 of them were beyond help. I cut 2 and dipped in rooting hormone and stuck in dirt to try to save them but who knows. They were Hindu Kush and now their gone. I had to order Papayas to replace them. Its what I am growing now and had no issues with so I have to try it again. Where did I go wrong?
I'll answer your question because you asked. I hope I don't come off as too preachy. You went wrong because you worried about about too much. In doing so you tried to solve a problem you may not have had in the first place.
What do I mean by that? I mean soil growers worry about PH far
too much. Constantly monitoring PH: That's a
hydro thing. In soil, PH testing should be done once, then repeated
only if problems arise. Generally speaking, soil-based plants will tell you if there is a problem with PH. With soil, you have a much larger margin of error in relation to PH. A luxury hydro growers do not have, thus the constant PH monitoring.
This confusion between soil and hydro techniques is one of my main critiques of grow sites such as RIU. This co-mingling of techniques led to your mistake in trying to adjust the PH of your water. Vinegar is used as an herbicide by organic growers and should be avoided. If you prefer water with a neutral PH, use rainwater.
+Rep to you for asking where you went wrong. I hope I do not come off as too critical, but I thought you deserve an honest reply. One which may help another grower down the road.
Good luck and good growing.