back again with more problems, bonbon HELP!

I finally figured out the rock wool cube problem and took off the plastic around the cubes and my plants started growing. The roots are doing OK too. But now they are really drooping. The leaves are green and look great except for this awful droop. I am using nft system. I check the ph everyday and am following instructions for nutrients. I don't know the strain, I started these from seeds, looks like indica, they are real bushy, looks like I have topped them, but did not. I don't know what to do. I thought the nutrients for a hydro system are balanced and that is all you need to use. There is no yellowing at all. What should I do? Thanks so much for any help anyone can give.

i dont think it's a nute issue,droopy leaves has more to do with heat build-up from the HID and lack of fresh air or stagnent air and too frequent watering cycles,add a couple of fans to the grow area and aim them towards the plants so there is some constant motion and slight movement of the foilage,check the temps in the grow space too....bonbon

Thanks bonbon for your help, I'll try that. I don't exactly have the "perfect setup" for my growing room. I do have a small fan running all the time, but don't have the fresh air coming in when the lights go off because of the temp being too cold. It is a nft system and I keep the water running all the time. That worked before with my other plants but they were from clones. All the instructions that I got with the system said that I should keep the water flowing constantly. Thanks again, I (probably along with alot of other people) really appreciate your help. Willow