FFOF soil grow lime green seedling

These are 3 gallons smart pots, the bottom 3rd filled with ffof soil and a teaspoon of Dr. Earth flower girl all mixed together. Then I took a Solo cup, put it in the middle of the pot and filled around it with ffof once again. Then filled the space where the solo cup was with ffhf. Soaked 3 seeds until they sank and then waited 24 hours and planted into the middle of the ffhf. 2 out of the 3 seeds came up and I lost the 3rd one (never came up). I am PH’ing my water to 6.5 and have watered some myco into the soil. One of my plants is vigorous and dark green and the other is slower growing (but growing) and all new growth is lime green, but older growth is slowly turning darker green. Both plants in the same bag of soil. Spider farmer sf2000 at 26” away, dimmed to 60%, 80 F and 60% humidity. Is the lime green from the ffof being hot? I’m perplexed Thank you in advance for all replies

IMHO FFOF is a tad too hot for seedlings. Get some other opinions on the best way to handle it. I prefer FFHF but a lot of growers swear by the FFOF. Matter of growers choice really. Good luck to you and yours.