Mate, your biggest problem from the beginning, apart from the fact you are/were not feeding, is the fact that you are not filling up those pots to the top. They're already tiny pots to begin with, and some of them look less than a quarter full. That gives you such a tiny margin of error with regards to everything; watering, feeding, ph, ec... that's a big part of why you're having problems.
If you want to guarantee their health, put them into a full pot of coco, water it with 0.8 ec of maxigrow (or another good veg/starter feed) on top of your tap water, and that's it. You're done. You'll have no more problems after that, except maybe with that amount of seeds, an overcrowded tent.
If you want to guarantee their health, put them into a full pot of coco, water it with 0.8 ec of maxigrow (or another good veg/starter feed) on top of your tap water, and that's it. You're done. You'll have no more problems after that, except maybe with that amount of seeds, an overcrowded tent.