I'm still searching for the thread with no luck. Imagine a room in your house with a giant window on the ceiling so you can grow all sorts of plants indoors. Now put a giant marble bowl in the middle of the room and make that bowl into a planted tank with no filtration except for the plants and only rely on sunlight to grow them.
Also, I am looking for the thread where a guy dug out a huge pond in his yard and filled it with different aquatic plants and even hooked up a co2 system. There should be a couple pictures of him swimming in it.