i don't do soil but I personally like number 5 the best. I have no idea how long that baking soda is going to sit in your soil and play around with the numbers. You've flushed......i'd get rid of as much of the bad soil as you can. (Feel free to ignore this advice )
Weedhound Reviewed by Weedhound on . Major pH Issues, I understand what's wrong I just can't fix it. OK so there are two parts to this problem, and they will both be gotten to in good time. This is my second grow, my first one went great bringing in 2oz per plant and while I was great with the pH at first towards the end I didn't screw with it 'till I had problems(which I had a few of), I just pH'd the water and feed. So here's my issue. I flushed a week before transplanting my 2 month old plants into 3gl pots and got the pH perfect at 6.5, the next week I trans planted and watered and Rating: 5