confused about cannister filter and saltwater setup


New member
NOOB alert!
Need some advice about using cannister filter in a saltwater setup. I was experiencing higher nitrates with a ehiem cannister filter and was adviced to unhook it as cannister filters are meant for use in freshwater tanks and use just 1-2lbs of live rock per gallon for filtration. However I have found a number of postings on his forum where users were trading cannister filters for saltwater.

I do not have a wetdry or sump/refugium hooked to my 45 gallon and was wondering if there is any filter media which when used in a eheim cannister can still do the job of maintaining water quality along with the live rock.

Should I just use carbon in the cannister e.g. chemipure or any activated carbon?


It's Dr. Goodluck Himself
Is yours a fish-only system? No sand, no rock? If so, then the cannister filter would, I should think, be necessary. But a FOWLR system is going to work and look better I think.


Premium Member
I do not like canister filters for reef tanks as they are far to easy to neglect. It is certainly not a required piece of equipment IMO, but if you already have one it would be good for running carbon periodically.



New member
I have 3 gal pico with a Fluval 250 canister on it. The canister holds exactly 1 gallon when the media is in the baskets. I use the prefilter pads that come with the unit, carbon in two baskets and ceramic tubes in the last. For water changes on the tank, all I do is stop the flow, unhook the quick release hoses, dump the canister and refill it with fresh salt water. Plug it back in and go.

Treat it like a closed loop that happens to have filter media in it. When its viewed as a supplement water mover to live rock, sand and skimming, you should be fine.