Yellowing leaves

Without a picture of the actual plant/s with the problem makes it hard to form an opinion. Otherwise it is a guess between inadequate lights, not enough nutrition or if it is only the cotyledons (baby round/non serrated leaves) that have gone yellow, then that is perfectly normal. Also, I am not sure why you are feeding "Flora Bloom" to days old seedlings, "Bloom" nutrients are called "Bloom" for a reason - they are for when your plants are flowering! Really need a clear, close up picture or three of the actual problem to be able to give you any meaningful help. Cheers.