I've been wanting to build a self-sustaining biotope/aquarium but haven't seen a good one to use as an example until I found this thread. The Walstad type tanks I've seen do look more like a bucket o'mud than your tanks does. AND, I am glad I found it after it's already 12 pages old/long, or I'd be constantly waiting for updates. I aspire to build a miniature version for my cubicle. A breath of fresh air from all the ADA Iwagumi designs I've seen on this site. Definitely a "Thanks!" for sharing. BTW, love your fish choices too.