just to add, pre-packaged PH up and PH down solutions are designed for hydrophonics, and should be used very carefully in soil or hydro.

if you take PH to far in either way, you are better off scrapping the soil and starting over. in other words, you should never use PH down to compensate for adding too much PH up and vice-versa.

your better using a "softer" natural ph adjuster added to the water slowly over time.
babystarbud Reviewed by babystarbud on . What's the best way to adjust pH? Ok, I figured out the problem. Ph is off. I transplanted one plant into new soil because she was small enough to do so but this other one is too big and she has buds everywhere. Her Ph is in the range of 4.9-5.1. Way too low. Two months ago I had transplanted her into a 5 gallon bucket. The soil I was to put her in was at 8.4 pH. So the lady at the nursery recommended how much sulfur to add in the mix to lower her pH before I put her in new soil. I had mixed a Ph adjuster to her soil Rating: 5