Until they fill out their initial pot, you need to be careful about feeding them too much. While they are tiny, just use a ml syringe and feed like 20 ml of 200 ppm nutrient solution right around the root zone, and as the plant gets bigger, start feeding more of the pot. Once a plant fills out it's initial pot, you can feed to runoff, but at that point it's ready to "pot up" so guess what? You start over, small plant/big pot, just feed around the root zone. All you are doing at this point is growing roots, don't worry about the plant. Once a plant has rooted out fully in a pot of coco, then you're on easy street, and you will need to feed min twice per day, though some people feed 5-6 times per day on an automated system with awesome results. Good luck!