Well slow growth can be caused by many things but judging from the conditions you listed above the only thing i can think is toxic build up on your media. This is also unlikely as if this is new media toxic build up would not have had sufficent time to occur. The right thing to flush with is something to break the bond between the various calcerous / binder materials. I use Florakleen for just this reason. Bleach's active ingredient is chlorine. Chlorine is a disinfectant and so is useless for this application. The book is great but I think we covered the bases here. I would flush with 25% nute concentration and see if there is any improvement. Also a photo would be helpful.

Herbus
Herbus Reviewed by Herbus on . ATTN: PRO HYDRO GROWERS!!! Your help is needed! (please!) I am looking for some help from someone here who is the PRO at growing hydroponically and who might be able to give a helping hand to a person in dire need! I am on my second grow ever, first turned out all men :mad: Second group of 4 is now only 13 days old. I do have some problems, and growth seems slow. If a PRO reads this and is willing to help me out, I would greatly appreciate it. Right now I have 4. first: looks great, just growing slow as all can be. some leaves have Rating: 5