Thought I would add a follow up about what I'm now experimenting on. I'm trying a plant filter on my axolotl tank. Took about 2-3 weeks for my plants to acclimate to the roots submerged, but it's a low maintenance way to keep my nitrate to 0. All the filter is, is a plastic window planter with a hole in the side for the output of my canister filter, some golden pothos, and peace lily I threw in, and an 18w desk lamp.
Just to clarify, this is a totally different tank.
Here's a before picture, when I still had my tank:
Heres what it looks like now that it's had time to acclimate
Peace lilly even started flowering
Even though using plants as filtration isn't a new concept, I thought I'd post the thread that originally inspired me to give this a go.
http://monsterfishkeepers.com/forums/showthread.php?t=404668