Im pretty new to this aswell.. but i am running a canister filter aswell for three months now and my nitrates are stable 0-5ppm
I completly replace the white foam pad in my canister every two weeks with a new one.
and once a month during a water change i fill a bucket and splash the other media stuff around in the basket.its amazing how much stuff comes out.
i removed my sump because of noise and am happy with the results of the canister.......so far that is