I feel honored by your reply. If I dose the water column, how often will I need to do water changes? I must be honest with myself. I just can't see myself trying to run hoses out the window or lugging buckets outside in the winter. My wife really wants Discus, but I told her it probably won't work because I don't want to do the water changes
I use a simple hang on garden hose to the shower for filling, draining goes outside for irrigating, but you can drain right down the tub also, no buckets, no water spills etc.
If she really wants them, make her do the work.
You do not need, nor should do water changes if you do the method I suggested there, read it, Diana's suggestion is the same as well, no water changes. Nothing builds up much because plants remove it, the rates of growth are very slow, so the demand for ferts is also correspondingly low.
Discus could be done, but it'd be under stocked or perhaps something more like this but at 135 gal to 300 gallon scale:
Then you could do water changes or not as long as the fish load/feeding was moderately low relative to total tank volume/plant biomass.
Problem is.......many over load the fish and then wonder they have health and plant/algae problems.