Ahh, Ok. you answered my question. I just jumped in on your journal and only read the last three pages and thought you already harvested the TS and were on a new grow. OK, Now I see where you're at. I'm along for the ride!
I also wanted to mention that my curiosity got the best of me after we spoke about PHing water Up/Down with Baking Soda/Vinegar...
So what I did was I PH'd 1 US gallon of tap water. I already had a gallon of water on hand from a few days before. It was left out overnight and then capped.
This gallon PH'd 7.6... I added 20 drops (about 1/ml) of Vinegar from a pipette and it PH'd down to 6.4... I capped it and left it overnight...
This morning I shook the gallon of water, uncapped it and tested it again. The PH is still 6.4 after about 18 hours. (It hasn't been a full day yet)
So, I didn't know where to post this and I wanted you to be aware of this little experiment so here it is. I'll PH once every day for a week and see what happens...