Thanks again for your constructive comments. To be fair to those that have, I'm not the one that has come up with the no-water-change aquarium concept. I've certainly heard of people doing it with different tank types, though not specifically with Discus, which would perhaps be the logical extreme to prove that it's a fully viable methodology . I'll have to get through a copy of Ecology of the Planted Aquarium book to broaden my knowledge on this particular subject before I'd commit to jumping off the deep end with this. But this approach is certainly not new or revolutionary, and the basis of it has kinda basically been happening for a few billion years now.
Can any of you tell me though which water parameters other than Nitrates you'd be concerned over though? Nobody seems to have quite answered what exactly they are concerned with doing water changes, so apart from Nitrates which are not so difficult to deal with I'm still at a loss as to exactly what people are worried about with this. Rodrigo, did the "Filter Guys" happen to mention precisely what they thought were the limiting water chemistry factors? If ten gallons of nylon pot scrubbers as biological medium weren't enough then I could always consider partitioning off the back 6 inches of the tank (instead or even in addition to the canisters), and filling that with dividers and pot scrubbers to easily create a 37 gallon biological filter sump maze within the back of the tank. I've seen a 40 gallon plastic garbage can filled with volcanic rock used as a simple and effective makeshift aerobic/anaerobic filter as well before, which could be housed under a tank set to eye level.
Achieving a solid balance of all the necessary planted tank parameters is a delicate dance certainly, as Intect implied, (despite that I'd nevertheless be utilizing some technological 'cheats' to help this), but I'd never heard the nematode thing before so I'll have to look into that.
BTW Warlock, black water recycling, via reed beds or more mechanical means is nothing new. Wisconsin allows recycled "poo water" to be used for washing clothes and cars among other uses. And Australia has been extensively researching its use for drinking water even, despite that doing so has certain psychological barriers for some.