I recently transferred my male gt, a male con, pleco and two danios from a 30 gallon to a 75 gallon tank. My question is what are some possible tank-mates ? The gt and con have been together for over a year. The con is a bit of an a**hole, so it has to be something that can hold its own. I was thinking some more danios and a firemouth..As far a filtration I have a penguin 350 bio wheel and fluval 405.