Actually, your tank doesn't sound very overcrowded to me. Your clown loachs and bala sharks could probably use a bigger tank eventually, but if everyone is getting along, I wouldn't worry about it all that much. My bala sharks and clown loaches are growing very slowly in a 125 gallon tank, and I think it will probably be a while before they outgrow yours. How big is the ghost knife?
I'd get the 30 gallon as soon as you can, since that's a good deal, and I'd move the neons and maybe one or both of the eels into that tank. I'd keep the rest in the hex. Your clowns would do better in a larger group, though... They're much happier with around 6 or so. I don't think your hex could really hold any more clowns, though.
What do the sunburts (
sunbursts, I'm guessing?) look like? I'm not sure what kind of fish you're talking about...
