Hey Rocksor
Yeah right filters won't render water changes obsolete but a bigger filter still means that your overall water quality is better and will stay better for a longer time. However, since this isn't my only tank and I am now restocking it and not starting completely new, I am already on a weekly water change schedule (with the occasional two week waterchange if on holidays or some stuff like that). I also already had some bichirs from a friend for a couple of months about a year ago since his tank cracked and he couldn't get a new one fast enough. Had no issues there with 1 senegal, 1 delhezi and 2 ornats (all being 20cm+), obviously the ornats couldn't have stayed in there for much longer but had no water quality issues there - this while being on a much smaller filter than now (about 3 times smaller- and yes I know, it's not all about the size
) I was feeding the every other day with frozen fish and they seemed happy and grew nicely.
I don't wanna sound like I wouldn't care about the inputs you give me, it's just what I experienced worked fine for a few months, that's why I am a little "let down" by the fact that you suggest only getting one of each kind.