Create a free Condom Ecosphere from stuff found in any fishtank. (To buy parts would be about 5$). It magnifies the fish and is very strong (condoms can hold up to 6 liters of water). The Circle Of Life... In a Condom! NOTE: THIS DOES NOT WORK AND WAS A SIMPLE JOKE/HOAX. DO NOT REPLICATE EXPERIMENT!
From Practical Fishkeeping...
Ecosphere aquariums, which the user is trying to imitate, are quite controversial. They are sealed spherical aquariums containing seawater, algae and some small shrimp and are sold as "the world's first totally enclosed ecosystem."
They claim that natural processes occuring within the sphere, break down the shrimp's wastes and photosynthesis allows the algae to produce oxygen.
Whatever you think of them, though, we really hope that nobody follows this person's advice and tries to create their own sealed aquarium using a condom. It really isn't going to work.