For fun, I am going to try to set up a 2.7 liter (.75 gallon) tank using only air pumps. It will use a modified hang on hatchery as the filter. Air powered skimmer and possibly a reverse Carlson surge device (if I can find space for it) or a regular Carlson surge device. Lighting will be a homemade LED array using my dead Pentium 4 heatsink and fan. Just wondering if anybody has experience doing this. I will be off to pick up the tank tomorrow and will update with photos if interested.