That sounds like an Nitrogen-Phosphorus-Potassium deficiency to me. I don't what what the N-P-K levels for superthrive are, or how much you are feeding... but i'm guessing you need to strengthen the solution.

By the way, I determined that from the charts in the Useful charts sticky. I highly recommend checking out some of the stuff in there.

good luck :thumbsup:
Faddenator Reviewed by Faddenator on . dying or heat? hey guys,This site has helped me with some stuff but i can't find the explanation for.. growing indoor, My plants are 2-3foot. I had just started to clone 2 weeks ago and now on 3 of my mothers 20% of the leafs are turning yellow drying up and dying..It's mostly the bottom leafs of the plant.. i use treatments such as end all,superthrive etc. any idea of what it could be? Rating: 5