> Do it Yourself> Filtration

Do-It-Yourself Undergravel Filter
Although this article was written by the Saltwater Aquarium Guides, it works just as well for a freshwater aquarium.

An Air-driven Reverse-flow Undergravel Filter
Bob Dixon wrote this detailed article about building your own UGF.

Filter Media
Lots of great ideas for inexpensive substitutes for filter media.

Sponge Filter
A simple sponge filter makes all the difference if you are raising fry. This newsgroup discussions covers how to make and keep them clean.

Wet-Dry filtration
Over a dozen newsgroups messages about building your own wet-dry filter. Good reading.