Yes firemouths can be a great addition to a GT tank.....I believe for a GT to be truely at his best you need to house him in a situation where he is the boss. Mine is with 2 Tiger Oscars and a Ornate Bichir in a 110gallon and my GT rules the roost and never gets picked on. I strongly suggest that you keep them away from more powerful cichlids like RD'S,Trimacs,Jags etc... They just cant hang, but i believe the true GT probably could but Gold Saums like most of us have certainly cannot.........By the way awesome fish Polo....My male also has a brillant bright orange i just need to bust out my digital camera and gets some better pics. That first pic i took was from my phone lol....