Aquariums are fascinating, but keeping one of your own can be a lot of hard work. Most people start small with a simple 10-gallon aquarium that has a few goldfish, a plastic plant or two, and colorful rocks. The aquariums in this list, however, are anything but simple.
The water overflows into a special basin that filters and recycles the water from the bottom. With no visible hoses or filtration equipment, this aquarium is the closest you can come to snorkeling in your living room.