First time Coco grow- Seedling turning yellow

[CraycrayQ]

Ok so this is my first attempt at growing in coco. Before this I have always grown in FFOF. I have a 7 gallon smart pot that is filled with general hydroponics cocotek, and about 30% perlite. The strain is amnesia haze autoflower by ILGM. I popped the seed using the paper towel method. I added some nutrients prior to planting, which were the general organics line and I added nutrients according to the feeding schedule, but at half strength of what the schedule says and PH'd to 6.0. Its in a grow tent that has a 400w MH grow light, but it is dimmed to 50% and is off to the corner of the tent. I only have 2 spaces for plants and one is specifically for flowering and the other is for all the other starting plants. The temps are high around 85, and has really low humidity right now (15-20%) because if the outside temperature and the houses heating. I made a humidity dome for it out of a plastic bottle and sprayed some water on the inside to keep the humidity around the seedling higher. The seedling popped out of 5 days ago and the past 2 days I've noticed it has started yellowing. Im assuming I probably gave it too much nutes. Is there anything I can do to help it or should I just wait it out until the plant grows out of it?

[Cronk]

be careful using nutes so early. first week they get very little if any, maybe 1/4 strength or less.

The definitely get cal mag full strength. Without it they will brown and die.

also, If you can bring the temp down just a bit until they get going it may be more comfortable for them