Sorry, but I'm too lazy to redo what's already been done. Go read my journal (very detailed) here...
http://www.apsa.co.za/Forum/index.php?topic=342.0
I stopped posting long ago, but my aquarium is still up and running with ZERO maintenance. I don't clean the filter, and I only top up the water when the levels drops (once in 6 months?) Oh yes, and the light tubes are almost 2 years old.
I also have 2 tanks outside with no heater, filter, or lights that I set up in exactly the same way. I have eleocharis parvula growing quite well in there - despite everyone saying that one needs light and co2 and a heater to do so. hahaha!!!
For those tanks, please go look here...
http://www.apsa.co.za/Forum/index.php?topic=1719.0.
The secret with successfully doing an el natural tank is use natural soil, natural gravel, loads of plants and then DON'T MESS WITH IT!! Let it evolve naturally.
The proof is in the pudding. (my photos)
cheers!