I think it's naturally staining. I've had root rot on the plant beside this one and can noticeably see a difference. Ph has fluctuated in the past week or so when I was out of town, but is stable now at 6.1. I don't know the ec/pmm.
Okay I was scared of the over watering so I put all four back in the first tote, I'll have to get another air pump to run both. The other day the new growth was light green so I took that as they wanted more food, only at 1/4 of the recommended dosage for seedlings.
I have 4 seedlings all that have started curling their leaves. They are only at 1/4 of the recommended dose of GH nutrients. Ph had been around 6-6.5 the part few days. Anyone got an answer?