What should I do with my Cannister?


New member
So... I convinced myself that I needed a cannister. I got an eheim in September, and followed the regular maintenance schedule. I'm really conistent with my tank maintenance, but 2 weeks ago I started getting cyano, and water changes had a green hue in the waste. I was also getting a film on the top of the tank that my overflow couldn't seem to get rid of.

I broke down the cannister for a thorough cleaning (this is at 4 months, and the maintenance schedule recommends that this be done at 6-12). Well, it turns out that my tank was doing the best that it could to clean my canister (instead of the other way around). The thing was full of detritus. I broke it down ad changed all the media, but it's obvious that my system is overwhelming it.

I moved the inlet and outlet from my display to my sump, so that it can run after the filter sock, but I'm not sure if this will prevent it from being overwhelmed.

I feel like I need the thing, because I only have room for sump and fuge that are about 20 gallons. Am I right? If I don't need it, what should I do with it? Sell it? Use it for running carbon only?


Premium Member
I think the best thing you can do is not use it at all or if you want to use it...at all...run only carbon...and that's a lot of carbon. I'd say that so long as you have at least 75-pounds of live rock in your system, and you're Octopus skimmer is working efficiently, don't even bother using the Ehreim. Oh, you can set up a freshwater tank and use it on that and it would be fine. But, if you want to run carbon, get a reactor for that like you would for phosphate-removing medium. Those will hold a more reasonable amount of carbon.