Ph going in is supposed to be 6.4 but I don’t really know I was using a 12$ ph meter got a better one now though the soil is fox farm ocean forest and ppms are between 1000 -1200 I’m using purified water cuz I have hard water so I’m adding in calmag 2ml per liter usin the advanced nutrients 2ml per L and one tbsp of molasses just started 2nd week of flower today and noticed a day or two ago my soil ph was high in the 8 range so past two days been using just water and vinegar with low ph to bring it down
Personally, (from recent experience) I would try something other than the acetic acid (vinegar) because it might not be noticeable to the naked eye in small quantities, but please believe me when I say, it's highly toxic and deadly to the plant. Too virtually all living plants, actually.
Acetic Acid is BAD, BAD, BAD!!! and it soaks readily into the plant tissues, and is impossible or nearly impossible, to remove, it's got to be detoxified though a metabolic process, which is taking up vital energy.
Go with phosphoric acid, sulfuric acid (#The Best choice for starters, IMO But use proper precaution), citric acid, ascorbic acid, gibberellins, hormones, auxins, cytokinins, humic/fluvic acid, even small amounts of salicylic acid (if you can get it to dissolve, personally I use glycerin, then into water). Anything, besides vinegar. Something the plant can actually metabolize and use, something of net benefit.
At one point I figured it could possibly be converted into 3-indoleacetic acid, (biologically useful) but no dice, there simply is no mechanism that exist for that conversion. IMO, it's just a poor choice among so many other better ones.