Some of the tanks/pools...

[GreenSpottedPuffer]

My dream "tank" would actually be a pond that is 1/4 reef with a drop off and the rest sand for sharks and rays. I think it would make a wicked display and perfect for top down viewing if you stocked the reef with sps. My idea would be to do mostly caps and tabling acros. You could just light the reef area heavily and leave the rest a bit more dim.