Do you mean a regular
hob or canister filter with carbon, floss, maybe biowheel?
If so, they are alright on some tanks. Maybe on a
fo tank. I have one on each of my tanks but have removed the floss and filled them with
lr rubble instead. If you have plenty of
lr and a good skimmer you don't need a
hob except maybe for the occasional carbon use. If you have a sump you can put the carbon in it and not even have a
hob. I only keep the
hob because my heater is part of it(tetratec 500 w/200w heater.) otherwise I wouldn't even have it. I also have a
hob aquaclear300 that's been converted to a refugium. If you already have it, it can come in handy but if you are planning on going with a reef setup, save the money for a good skimmer and live rock.
