All seedlings are yellowing

[tadaa]

I can't figure out what the cause is. All my seedlings have yellow leaves. I know it's not the soil because I've used it before, and I'm using 2 different kids of soil and all my plants are yellowing. I have a 600watt light on them, and I wonder if it's too much. It's about 2 or 2.5ft away from them right now. I think maybe I am underwatering?

[Lady Vapor]

How much water, container size, and how often do you water? Temperature?

[tadaa]

The pots are about 5 inches in diameter. I water them once every 3 days or so. I started my other plants in the same pots and soil and they did great. The temp is the only thing that may be a concern. Im getting a thermometer tomorrow but I would guess about 85.

[John Doe]

Are they clones? the bottom leaves from my clones did this too...
I hear its almost normal...
My guess was the plant was using all the food from those leaves helping the root system progress

[tadaa]

No they weren't clones. I made my own mix of miracle grow soil and a soil with no fert in it. The miracle grow soil did wonders for my plants before, but burned them after 4 weeks or so. This time I made a mix of the perlite, regular soil and miracle grow soil.

[John Doe]

Im not sure but it could be the MG... we need some pics bro

[u.g.u]

I would pull your light up a bit it is not a defciancy because they are seedlings in new soil.