I came across a product called EcoSphere, which is a glass bowl sealed-off, with some algae, shrimp and micro-organism living in it, and was immediately enchanted by what it represented. A tiny world that would supposedly sustain itself. Unfortunately, after some more browsing on the subject I found out these poor shrimps most likely die of starvation and pollution. I don't want that, but I am really intrigued and I am trying to find out what options there are for creating your own, larger, semi-self-sustaining biosphere? I came across some videos that showed closed off bowls that even had fish in them and were self-sustaining, but I found it pretty iffy and can't imagine it would be very healthy for the fish. What possibilities are there to aquascape and have fish without heating, filtering and CO2?