They are 4th week of veg. They were hit hard with mites, thanks to a dirty supplier. We used avid and boomed the heck out of the area. As far as rate of nut, are you talking about amounts? I hand water each cube. Since I am new with rockwoll I was instructed to feed them twice a day. I just soak the cube till i get run off from each cube. I did back off on the schedule, and let them dry out. Took a 1-2 days depending on the weight of each cube. I am running 750 ppms and the lights are on 24 hours. I am not a fan of 24, but I am listening to my partner, totally a new way to grow results from it are off the hook.