• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Canister Filters


Jul 11, 2003
I want to know whats going on with these, because on reefcentral.com they seem to strongly appose these filters. They say that if u use them than nitrates will rise, is this true?? Its starting to worry me (seeing as i have a canister filter) :?

Yeah i agree with vulgaris on this one... the cannister is fine, all filters are nitrate factories that's why we do water changes etc...
I agree, I have a canister and have had no problems. Actually I love them, but I also keep up with maint. so it could be true for any filter if you dont keep up with it :wink: Canisters are great!!!!!!
When you're going to a place that specializes in reef tanks for advice, you should remember the differences between reef tanks and octopus species tanks.

If your goal is to grow sensitive corals, then you need the nitrates as low as possible. This means avoiding canister filters.

Octopusus, on the other hand, aren't particularly sensitive to nitrates, and produce a lot of them as a by-product of being messy eaters.

That's why reefcentral says no canisters, but we say they are fine. It is important that you do regular cleaning of the canister, to avoid the nitrates growing to unreasonable levels. I try to do this about once a month in my tanks.

My canister has three sections - a sponge to trap particles, carbon to absorb compounds from the water, and a bag of porous ceramic bio media.

For my monthly cleaning, I rinse the sponge thoroughly under running tap water, squeezing it until the water coming out is clear. The carbon needs to be replaced. I keep the carbon in a mesh bag (you can use the foot from a pair of panty hose for this) so that it's easy to deal with. The bio media should not be disturbed much so as not to kill the bacteria colonizing it.

The thing I don't always remember is to have an extra half gallon of fresh salt water to re-fill the canister with after cleaning it. Otherwise, the tank ends up low when I'm done.

The sponge isnt the biological part of the filter, well it will get colonised, but its main job is to physically catch waste to prevent it blocking the biomedia, so rinsing it in tap water isn't too bad....

Depending on your tank and octo I'd just keep an eye on the flow coming from your filter.. and clean it once it slows down.. so maybe cleaning might be every 6 months or so... always worked for me :smile:
Hmmm. I wash out my sponges in tap water (I am sure, killing millions of bacteria in the process) and have never had any problems. I don't use carbon though...
I have always liked canister filters for ANY kind of tank, as long as used in moderation (especially after a good scrubbing down of the sides!)
Colin said:
..so maybe cleaning might be every 6 months or so... always worked for me :smile:
i think that's a bit long, i've seen it get major build-up in 3 month's, but hey it depend's on the owner, not everyone uses the same feeding techniques.
YEs, it depends entirely on the tank.... the only way to be sure is by keeping a close eye on the amount of water being put back into the tank
Are you taking care of three octopuses in a lab, or are they yours at home? Did you say one was a vulgaris?

Oh, and you might want to look at Ceph Care under Site Contents - pics of some of Colin's octopuses and cuttlefish are there.


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