Yes. Often the belly area gets eaten, maybe the rest decomposes or maybe that is eaten too.Would the danios eat another dead danio?
It's a small amount, I was going to guess at about 6mg/l but Essjay's link should allow you to calculate the correct dose. Definitely temporary, once the cycle is established you won't need it.I found some API aquarium salt so will get that. How much would I need to add, every water change and is this a temporary product or something I should always be adding to my aquariums?