First DWC grow i ever did i bought three Think different, they all popped, and were all roughly the same size a week on when they were ready for their final homes. I couldn't bring myself to bin a healthy plant, so i cut the lid off a 3L bottle of cheap cider and wedged the 4" cube in there with...
Yep, actually, my maths is pretty dreadfull. I run 20l pots, full to about 17.5l, and work on a minimum of 6l per min. I am super paranoid about pythium though. Provided your res temps are nice and low you might get away with a smaller output. 3 seems low however.
Cheers for the response. Light intensity was my initial thought, but then why lower leaves first, and why only in the DWC plants, fred on the exact same nutrients? Seems odd.
I'm currently growing 2 plants in dwc and 4 in coco, both 17.5l, (think different and bulk smash) equal splits between the plants. PH has been between 5.5. and 6, room temperature has been 22.1 highest 19.1 lowest (teperature outside is about freezing at the moment). Plants are on 24 hour light...