thought this was kinda neat!
 

This tank is pretty well self sustained aside from general maintenance of course! it is constantly fed from the fjord and houses local saltwater fish from the area. I thought it was pretty neat, seeing as how there isn't really any filtration on it, but instead new water coming in and old going out. pretty cool DIY Idea, if you lived right on the ocean I suppose!

http://www.youtube.com/watch?v=iVDKE...eature=related