Replying to Need Help With Science Project - Hydroponics and caffiene

So I just did this year long science project where I grew special plants in a large indoor hydroponic garden and added caffeine to some of the buckets. The plants with the caffeine didn't grow much but the regular plants grew a shitload. I have searched the vast reaches of the interweb but nothing has been any help. The papers due in like a week and if I can't figure this out so help a brotha out smart NS'ers. +K and major street cred for good answers.