Well this thread scored my attention 100% now. (who doesnt like freaks?!)
as for no filters...if you have adequate bio filtration, and by that I mean enough plants to completely use the nitrates in your water, then if its working and the fish are happy by all means do your thing girl.
Water changes however...are 100% neccessary in my book...even if you aren't removing nitrates from the water with them you are taking out hormones, and replenishing minerals that have been used up and absorbed by the plants and fish in the tank.
Ponds have a different chemistry and biology than in home aquariums. The shear amount of water vs. livestock is enough to negate water changes and filtration is handled more naturally in a pond exposed to actual nature lol.
