I think your light is ok, I personally get my sprouts off 24/7, as soon as they pop, to 20/4. At about 5/6 nodes, I go to 18/6. I have always seen better root mass with some darktime. I'm in no way saying 24/7 dont work...but for my gardens, I use the above light pattern.

One of the reasons I gave soil the boot from my gardens, I always had a hard time getting a decent PH from it. I'm strickly ProMix, PBP nutes, and havent worried about PH at all since then.

I'd add a bit of dolimite to her, maybe mix it in water first, and water her with it...but looks like your to hot ph wise. Maybe a 1/4 strength feeding.

Maybe use spring water or distilled till she perks up. Good luck man!!