Regarding the Bio Tanks; I noticed that it looked oddly familiar in the picture I posted on the blog. (You don't see the resemblance when you're sitting here, looking at it in 3D.) But it isn't complicated. Aside from squirting air into them a few times a day, I just drop in a dollop of pond goop every week or so. I don't know who's eating what, but they're all still alive in there.
The 2nd picture (above) is by Alex Thomas of SwanCam. He stopped posting a few years ago and I really miss him. The 1st picture is my rendition. I decided to 'Van Gogh' it. (Click for full-size images.)