GMSgrowsanswered grow question a year ago Just small amounts around the newborns. Spread it farther as it starts to grow good. Once roots have filled the planter if your in soil, probably 1 to 1.5 liters will do, or water until you see a tiny bit exit the planter. If your growing in coco or soiless, about 2 liters should give you 10 to 15 % runoff from the planter. If not, add more until you got your 10 to 15% runoff.