I've got a 55 gallon tank that used to be home to my turtles when they were tiny. I'm currently getting it ready to use as a fish tank. I have a ten gal tank and am familiar with the basic care of fish. My question is, what fish do you all suggest for the 55 gal? The tank is deep rather than long: it's about 30x18x24 (that's an estimate--can't find a ruler). I'd like a nice mix of fish but don't trust myself to not overstock it. I'm not interested in any overly agressive fish.