I like the mattenfilter which you could think of as an adaptation of a pond filter to an aquarium, or as an undergravel filter "magically" standing upright on the back of the tank, doubling as a background.
Here's a link. Look at the pictures before you try to absorb the Teutonic theory and mathematical analysis of how it works. Trust me, it works great. Once you have used the Mattenfilter, and you buy another $400 canister filter, you will know you bought it to impress other aquarists, because you already have something that works better.
http://www.janrigter.nl/mattenfilter/
Here's a link. Look at the pictures before you try to absorb the Teutonic theory and mathematical analysis of how it works. Trust me, it works great. Once you have used the Mattenfilter, and you buy another $400 canister filter, you will know you bought it to impress other aquarists, because you already have something that works better.
http://www.janrigter.nl/mattenfilter/
