unfortunatly that the problem with big plants and indoor grows, lights only efficiently penetrate about 1.5 ft from canopy. This makes lots of tiny crappy nugs, or lots of lollipopping at week 2, which is what I do when my plants get to big. i had the same prob with my last grow, though the top colas were huge, the bottom 2.5 ft had barely anything. This is where perfecting the sea of green method comes in. This time around I am going for only huge top colas, wish me luck, and good luck yourself.