Burnt and yellowing

that little seedling is looking hurt. Its showing signs of stretching as if the light was not close enough. and something that lookds like nutrient burning on the tips of the new leaves. If the soil was coco was it buffered before hand? If not it needs a heavy dose of calcium and magnesium. But it may drown out the seedling if its just coir and nothing else like perlite. If it was not washed before hand as well from a less brand, it will have a high salt content that could also hurt the seedling. Was the coir fortified beforehand with some food for them to get zero nutrients so fair? Coir is void of nutrients, so it needs to be amended. Let us know your responses to this or PM me. Best of Luck,