Molasses will work in hydro too, but personally, unless I were COMFORTABLE running a TRUE hydro-organic regimen with healthy reservoir flora (beneficial microorganisms), I would stick to something like Sweet.
6.5 is a perfectly fine pH for coco and there's no need to fret over it if it stays there.
stinkyattic Reviewed by stinkyattic on . pH in hydroponics (auto-drip coco)??? I recently got my plants a hydroponic system, but keeping the pH level in it at 5.5 - 6.0 is really difficult. The water with nutrients in it is at about 6.8, and then we add "GHE pH down" which lowers it to 5.5 - 6.0. But after a few hours its back to 6.5. Could the problem be that the plants are eating up the nutrients and leaving the pH closer to clean water pH? :P And should i just leave the pH at 6.5 ? Oh btw, plants are just about 10cm tall, growing a bit slow compared to what i'm Rating: 5