[wake49]

I would worry about getting the 300 gallon tank you need to house both of those groupers before getting any other life put into this 55. This tank is way too small for your current stocking list and I am surprised there isn't more aggression (although it may be taking place when you aren't looking). Keeping marine species in their adult size tank from the minute you obtain them is much smarter than stocking with the notion of upgrading later. Things happen and maybe you can't upgrade, and the creatures also will have compromised immune systems and security issues (causing stress) from day one.

Please upgrade to a 300 gallon before adding anything else. Your fish will thank you for it.

 

[wake49]

A 250 would be fine, but those get to be some rather large fish that can almost two feet and show aggression to tankmates if in smaller tanks. They also eat almost anything they can fit in their mouths, so when they do grow up, they should be the smaller fish in the tank. Otherwise you can say goodbye to some expensive marine fish ;-)