HELP! Nitrogen Toxicity?

[bonghits4buddha]

Nearest I can tell this is Nitrogen toxicity, any opinions?
It's hydro drip fed. Ionic nutes, standard ratio, no extras except some Bigfoot mychorrazae a few weeks ago. Full HID lighting, temps are hot, but not extreme. One varietal displays this clawing, but it is not on every part of every plant. The other varietal that I have displays no clawing whatsoever, and is also a little bit fuller. Both are indica dominant. I think this might be Nitrogen burn, because I can't for the life of me think of what else it could be. I flushed the plants with clear water and they are now being fed a slightly lighter blend, but it's too early to tell if this will be effective. Opinions?

[mactheman]

if you cut down the N every thing should be ok ,,mac

[Toker1]

I don’t see darkened leaves, leads me to believe this is a case of overwatering.
are those rock wool cubes underneath those plastic covers?

[bonghits4buddha]

Yes, that's rockwool. It's in a top drip system with good drainage, I was under the impression that it was nearly impossible to overwater in that case. I'm going to reduce the feed times and see if that makes a difference. What schedule should I use? Scouring the internet I get ranges from twice a day for 1 minute, all the way to having it on 24/7

[Toker1]

It depends on your ambient conditions. You may have to experiment a bit to see what works best.