I'm gonna have to say it's the amount of nutrients your using or rather the amount of nutrients your not using. First I have to say that I am not familiar with superthrive and that you didn't list the amount that your using. I do have a lot of experience with GH 3-part, and your only using 2 parts. If you want big fat buds follow this link.

http://boards.cannabis.com/hydroponi...iscussion.html

It is a little confusing so if you have questions about it ask them in this thread
socialistpete Reviewed by socialistpete on . How do ya get such HUGE buds?? we grow in a cabinet 2x3x6 with 400w hps light we do everything according to what we read here. The one thing we can not figure out is HOW DO YA GET SUCH BIG BUDS? We r on our third grow and so far nadda big bud grown.Is it in the Pruning or letting them grow with no pruning .We see the pics on here and scratch our heads HOW. a friend of ours who grows outdoors mainly doesn't prune and gets huge buds but that outdoors. ANY Hints , clues , suggestions will all be put to good use. Rating: 5