Again, thanks for the welcome. Yes, having plenty of free time is certainly an advantage. Gazing dreamily into the shimmering, restful light of an aquarium allows for some light meditation, and stimulates thoughts on how our world has changed since the days since I made my first steps into this hobby. A friend owns a pet store, which specialises in tropical fish. Near the entrance, he has a small display of how it used to be - a small iron-framed tank, topped with a cover made out of aluminium folded sheet, with a mechanical air pump rhythmically spinning its chrome wheel. The small cylinder hypnotically dancing to and fro, like some miniature "nodding donkey" Texan oil well. It certainly creates some interest amongst the clients more used to today's technology.
It didn't take long before I noticed the main drawbacks to the Bio Orb. It felt distinctly top-heavy, atop its table, and I never felt too comfortable passing near it. It just looked unstable. For the volume of water, it had a very small bottom area, and because of its shape, the substrate was out of sight most of the time when looked at from the side. I had some small shrimps and a crayfish. Being bottom feeders, they were difficult to spot, but when you did see them, they and their fellow tank inhabitants looked distorted, because of the magnification of the glass. The perspective was completely wrong.
From a practical point of view, the "rocks" that come supplied don't seem to be suitable for the bottom of an aquarium. Their irregular shapes leave great cavities between them, providing spaces for uneaten food to gather. The filtered section underneath seems to be the small raised disc in the centre, the remainder of the base being unfiltered, allowing debris to gather between these rocks. I had cause to clean the orb out after only two weeks, and was amazed at the volume of matter than soon soiled the water as soon as it was disturbed.
I offered it to a friend for his plants. I wouldn't recommend it for fish.
I have just bought a 64 litre (14 gallon) "Panorama" tank to replace it. Being rectangular, it has a much larger bottom area than the Bio Orb, and it is more visible. It also comes with a new-fangled special filtration system, which I decided to ditch in favour of a traditional undergravel filter. I intend to keep African dwarf frogs and some small shrimp in it, so hope to reduce the strong suction and water movement to a minimum. I can also walk past it without fear, knowing if I accidentally bump into it for any reason, it is more likely to remain upright!