Twin Tube tank?

[bukster]

you would have plenty of water flow and only need one heater if you use a w/d. run the return on one side and a overflow on the other. IMO i think it'd be awesome for some smaller s/a fishes. cories, rams, etc.

 

[]v[onster Loaches]

Have you seen the fish bridges before? They are just a clear tube large enough for fish coming out the top of one tank and going into another. You just need to suck the air out to prime it, then its a siphon. A pump in one tank going to the other will cause a current flowing back through the bridge.

http://gizmodo.com/346527/fish-brid...iums-if-only-fish-were-smart-enough-to-use-it

You can make something a little simpler of course with just some clear acrylic or pvc pipe with turned down ends. You could use whatever tanks you want and dont need to drill them or anything. They would have to be at the same height though obviously.