Is that Coco. My seedlings looked like that when I used Coco. I found out it was becasue the Ph of my water was 7 and I shoudl have been lowering it. As well Coco requires you to use nutrients fairly early cuz there is none in the soil.

I am still a new grower though So I could be mistaken. Thats whata seed guy told me when I went to get some new beans.

I'd use Promix its designed to be used with normal Tap water Ph7 Neutral.

My 2 Cents

Good luck

kd