Did you get them from Aquascape? how big is the elong?
with serra they often won't eat rightaway, need to give them sometime until they get more comfortable.
just let them give use to the tank for few days then try again. sometimes they won't eat until they think there's no one watching so you might have to leave the food in tank for a bit. depends in size and condition of the fish they can go some time without eating so I wouldn't too worry about it.
