GMSgrowsanswered grow question 5 years ago 400 ppm to start max then when you see new growth and they start to get a little bigger, up it 100 ppm at a time. Good way to know if your plants need more food is to watch the stems of the leaves. If it isn't a genetically purple traited plant,those stems should be green, when they start getting red or purple your plant is telling you she wants more food. I would also put ph water through your cocoa once in a while to keep salt from building. Cheers