I have a pair of bn with my discus and have never had any problems with the water quality. Just dont over feed them is all.
Well... what I'm going to do is stock the tank quite slowly anyway, so I'll be able to judge the levels of pollutants.
Half of the media in the filter will be from a four month old filter, so the tank will be instantly cycled for a low low population.
As the rest of the media matures I'll add small quantities of fish.
Once I get round to the discus the filter will be well matured.
That's the basic plan.
From the results of the tests on the water I can evaluate whether I can add a bn or not...
The tank comes with a 900 l/h filter in the hood, but has the pipework to add an external one, and I think I will be adding a 2.000 l/h one from the same company further along the line if I fell the need for it.