Curious Im sorry but I cannot help you with your ph question because I do not know how to accomplish that in soil. If you want to change the ph of your WATER that you water them with this is how....but I am not sure if it is the water or the soil itself that needs to be exact.

To raise ph in water use baking soda (I would NOT put baking soda in your soil curious!)

To lower ph you can use distilled white vinegar....again not something I would add to the soil itself.
Weedhound Reviewed by Weedhound on . seedlings seems stuck hey all, i'm using a 400w hps w/ an Mh conversion bulb thats 24in. over the top of the large parts about 27in. above the small, the one''s in the big pot seem stuck...should i move them closer so they get much light, they just all seem stuck and pointing sideways instead of upright, i only have 9ft squared, u think i should move it closer or let it go as is....thanks Rating: 5