I think the term 'organic' in this case- you mean 'soil'? There is organic hydro and the pH is in the range you gave for regular hydro. In soil, 6.4-6.8 is good, in soilless, 6.1-6.5 is more what you are after. Your goal is to get your RUNOFF to the correct pH, so you will have to check it regularly and adjust the nute solution going in, because it interacts with the soil as it goes through, and both pHs change.
Of course, if you re-pot frequently, into a soil or soilless that is at correct pH, you don't have to worry so much.
stinkyattic Reviewed by stinkyattic on . PH Problems Thought I'd share my trials and tribulations with my runoff ph. Mother Plants: used to not worry about runoff as vegging plants have never exhibited any signs of distress. Until recently, I noticed burnt leaf tips awhile back. Flushed with Clearex and they came right back. That's mostly because she is rootbound. A week later I checked the runoff and it was still 5.8. Since then I've fed and watered with 7.0 and runoff is up to 6.2. So it seems to me that you can veg a plant and not Rating: 5