I think it can be a lot of fun with the right jar. Attached is my favorite one I had running, a lone pea puffer and snails. The duckweed kept the water clean and the puffer ate the baby snails. It got so spoiled on snails that it wouldn't accept blood worms or baby brine, it would only eat the baby snails. All I had to do was feed the snails the right amount and remove duckweed as it grew to maintain the tank.