Can we grow discus without all the waterchanges? Absolutely! Think of it this way, you can filter just about any water to be safe for your discus with an RO/Di unit? So you could put an Ro/Di unit directly on a tank with a dosing pump to dose added minerals to the aquarium. I'm sure many have heard about how Alexander had previously used a recirculating system using RO units. Well, obviously just chucking some Ro units directly on the aquarium because, well, it wouldn't last long before the prefilters were clogged. It just wouldn't be economically worth it. However, we could use a filtration such as DR Novaks Biocenosis clarification Baskets to control ammonia, nitrite and nitrate. Then, we could use a combination of the methods I had mentioned above for dissolved organics to maintain safe levels of dissolved organic carbons. The question is, how easy to get a balance where enough of the dissolved organics is removed? Well I can not answer that for you. I personally am very optimistic about it. If you are to rely heavily on cleaner foods, and refrain from using beefheart, you could significantly reduce the organics load on the tank.