my plants are only 3 weeks into flower, and they are losing lots of fan leaves. There are barely any large fan leaves left, the only leaves that remain are the smaller fan leaves that cover the stems and the growth/bud tips. The bigger ones shed just less than a handful of leaves a day. Is this normal? If not.... how the hell do I fix it? I have been giving them lots of N, which greens up the tips, but does nothing for the older leaves. Is this gonna fuck up my plant before I am able to harvest?