Alright might be jumping the gun here a little but a few of my seedlings are are possibly showing a slight deficiency. The newest growth is becoming yellow. Plants are under 400 watt hps. Grow medium is 3 parts organic potting mix, 3 parts worm castings, 4 parts vermiculite. I have been watering with rain water. Havent been able to get a ph meter yet. Next week for sure. Haven't fertilized yet. ideas or suggestions? Thanks a bunch dudes and dudettes!