It sounds like you have a potassium lockout as your first indicator of nute problems.
I have heard of the pure blend users having problems lately. Apparently the company did in fact change the formula. You might want to do a search or look at some other grow forums too for more info on that.
Your reservoir sounds very chilly. Roots can't uptake nutrients effectively when the water is too cold. Stick a fish tank heater in there and get the temps stabilized in the low 70s.
stinkyattic Reviewed by stinkyattic on . i have a question about nutes i have a question about nuts Rating: 5