Looks like all their soils are full of synthetic fertiilzers “derived” from a bunch of good looking organic matter which has been processed into synthetic fertilizer.
Nothing organic about it, they’re a hydroponics company.
“Mother Earth” they call themselves, lol. Hilarous.
Find a brand that is actually organic, gotta read very very carefully, every word on their labels.
I believe in that nutrient burn risk 
, the plant is too young for all the food she is receiving, I would slow down a bit and see how it reacts … 
Ok cool I didn’t water them yet just due to that fact … gonna try and push the water till Wednesday and by then it’ll be her second week alive
Leave that seedling alone. Don’t add anything more. Seedlings need nothing but a little water and a little light. Your issue is overdoing. LITFA