Hi reptyls and welcome to Simply. I think you will find a 54 gallon a little small for discus. If you have not kept discus before they are large fish in both length and height. Discus also need to be kept in group of generally six or more due to being a shoaling fish and to spread aggression across the group due to being cichlids. If you have not seen Al's one hour video on keeping discus it is well worth your time. You can find it here in the first post of this thread http://forum.simplydiscus.com/showth...CH-THIS-VIDEO!.
Pat