Hey, I have 2 plants going. They are about a week old now. One, is having yellowing show on one of its original 2 starter leaves. You know, those two small very smooth ones. I tried growing before a couple months back, and had this problem. It was the miracle gro I was using at the time. I dont know what it could be now, though. I'm using Fox Farms Ocean Forest Potting Mix with nothing added. No nutrients yet. Temps are probably around 85. 111 Watts in a micro grow. From what I've read, it could be N deficient, Mg deficient (Cant be either of those since I havent used nutes.), or over watering. I didnt think I was over watering, though. Anybody have an idea?
At a week old the starter leaves [cotyledons] should not be yellow. Most likely your FFOF Soil is too hot for them and starting to fert burn them.