sick leaves on Nebula seedlings

[lunker]

5 nebula seedlings , 3wks in pro-mix soil in 5" pots , under 400WT.halide at least 3 FT away, 1200 lumens at plants. into 4th wk. now & big fan showing stress, curling down, cracking along edges, no yellowing or brown tips, 450 ppm feeding regimen with hrdro balanced nutients two part mix A&B. lst and 2nd wk under 230wt flouros moved to halide wk 2.5, flushed plants today with h2o at 6.8 ph. tested the runoff (ph 5.9 and nutes at 450 - 500, plants vary in ht from 8 to 4" previous growth healthy and robust, appears that problem stated in lower fan leaves especially in smaller plants . room is ventilated and temp usually about 78 F humidity 50-60, have reduced 18-6 to 14-10 to promote female tendancies during last 2weeks, any advice on remedying this problem greatly appreciated, sorry but have no photos.

[luvtogrow]

Growing Nebula for the first time myself. I'm at day 35 flower today, but have a pic from few days ago(really too hot!), of ak47 and nebula. Nebula have bigger colas than the AK but are smaller plants and leafy. How is your Nebula doing? Any pics?