Yellow Seedling

First timer here. Been reading around for a while though. Thanks to All of the contributors. This little guy is going in a 2 gal DWC with hydroton, no rockwool. Little over one week old. No nutes until today, changed res, now = PH 5.7, 300 PPM Dutchmaster Gold grow A+B, ADD27, zone, silica. LIGHTING = 1 X 90w LED UFO assorted spectrum, 4 x T5-HO/gro. Any info on the cause for this extreme yellowing, with dark brown on the edges, looks crispy almost. Maybe the light was put on them too soon ?? Thanks.

next time maybe use a rw cube.

Yeah the pebbles move and hurt the little roots.. you might want to give her way less light too.

Thank you for the input. I read about people having issues with keeping the PH regulated in rockwool, so I was just trying to avoid any issues with that. Looks like I didn't do myself any favors. Will use next time.

Rapid rooters work very well too for sprouting

I had some of those laying around, but I had bought them last year, never got the chance to use them, and they had this pale white film on them. So I just used a paper towel Can you just leave them in the rapid rooters and put that directly in the hydroton, or should you rinse the peat/soil mixture away before moving into the DWC?

Straight seed or clone into rapid rooter, soak, wait a few days you gotta keep it moist though.

I just soak my rw cubes in city tap water for a couple hours.

Thanks for all your input. Haven't found any rw around here but I did get procure some rapid rooters. I plan on ordering rw online and give it a shot as well in a few weeks. I guess it's safe to say the root system was probably crushed in the hydroton then? I started 2 at the same time and one is hanging in there but the one above is looking rough. It has not gotten any worse but there hasn't been any growth for several days. It seems to be at a standstill.

I have rw clones knocked down. Nearly 100% success rate and all I use is RW, and a container from a cake at the super market.
1 thing is to make your own hole in the rockwool, don't use the whole that is provided.