I had a magnum 350..ran it about eight yrs I think...then the impeller failed..Set it aside a year or two.. Got new parts including a new impeller and then it started leaking. I have yet to fix the leak which is a shame because it's the most expensive filter I've ever bought.
I'm hoping I can fiddle with it when I stay over night at my parents house so I can monitor it for leaks. Of course how I chose this filter is someone with oscars says I have a Magnum canister and I like it...So I was sold on it. Pre- internet days..
I have various whisper and I think they are aquamaster power filters...Some of them are probably twenty years old by now. Only have two running right now. All of them are quite noisey so I'd only use them for celler tanks.
Hmmm...I guess bottom line is..I don't highly recomend any of my filters.
When I become a rich massage therapist, I'm going to switch to premium Eheim filters or something like that.