You are probably feeding them too hard. If there's too much nutrients in the water, they can't take up any. I'd back off to like 700 PPM for a little while and see what happens. But they definitely don't look right, thats for sure. Hopefully someone will be a little more help than I was, but I would lower the PPM. As a rule, I never go over 1,200, and rarely over 1,100. I run mine around 900-1000.
The above post is fictional and should in no way be taken as truth.
If I were to grow cannabis, I would only do so to supply myself and my close friends. Doing this would take myself and my friends out of harms way by knowing the source of our cannabis, as well as take hundreds of thousands of dollars off the black market annually. It would also lower the demand of black market cannabis, and would ultimately help keep cannabis out of the hands of minors.