http://badmanstropicalfish.com/vivarium/vivarium.html
check out this link! This guy built a flase bottom viv and took pics to document his progress. Then after it has grown in again he took more pics. I remember last week there was a whole discussion on different ways to create a pond so I wanted to share this with you. I know it's not round but it is really cool so I thought it might help.

http://badmanstropicalfish.com/vivarium/vivarium.html