I have a 16" RTGG in a 450. She hates silver fish also. I have a 30" Black Aro that she pushes around and a couple 15" Bala's. She can't catch the Balas but every once in a while the Aro gets fed up and rips into the RTGG and she loses a few scales. Overall she is peaceful but defiantly the top dog (in her mind) of the tank.