Dual Canister Filter Cleaning Methodology?

When I clean my cannister filters I take great care to see that my biobugs are not harmed. I use prefilters on each cannister, and rinse that part 3-4 times a week so I don't have to open them up all that frequently.

When I break one open I do it when water changing- I rinse all the bio media in the tank water I just removed from the tank. I use Eheim media but any brand would be handled the same. I remove all the media baskets and stack them in the garbage can full of water to be discarded. Any tubing that needs cleaned is put into the bucket as well. Then I shake them one by one in the old water- rinsing them in it several times if it looks gunky. If media needs to be replaced I only do a small bit at a time. I use a hose brush on the tubing- all the implements are fish-only.

Once in a while I clean a filter without doing a water change- then I have to make a portion of water ready with chlorine/chloramine remover added, and temperature match to boot.

Frequency would depend on your bioload and foods used, but I'd think that doing them on an alternating schedule of one filter every two weeks would be plenty. That would break one open every four weeks- should be fine.

If you can possibly rig a pre-filter of some sort it makes a huge difference in maintenance- gets the tiny food/debris bits out before they can contribute to the nitrate production.

sounds about right to me......

i haven't really made a set schedule for my canisters and i don't have 2 on any tank atm. i do alternate them with the top filters tho, i will only clean one or the other. usually i can sort of "see" when the filters becoming restricted, the outflow tends to slow a bit and that's when i worry about cleaning it. i should probably clean it more but it just doesn't seem warranted... i also use a fairly simple setup, just the prefilter, some floss and bio-media.

We alternate cleanings.. Every other week seems fine..

The "old school" (promoted in no small part by Eheim, I hate to admit) of rare canister cleanings has serious flaws to me. First, out of the water column and out of sight is in no way out of the system - you are setting up bacterial and infusorian digestion of all the captured fish poop and leftover food inside the canister, with all the DOC, nitrates,etc. being returned in dissolved form to the water column. Second, if the canister's mechanical filtration is not excellent, debris can make it to the biomedia, or even if it is good mech, the fines/mulm from digestion of waste will move to the biomedia - which promotes migration of the active biolfilms of nitrification bacteria to the lumps and particles external to the biomedium and thereby is subject to being rinsed away (a variant of the dirty ungravel filter cleaning issue, but same principle and result). Finally, the clear water from decent canister function fakes out the keeper if they do not test (nitrate, pH, KH), so that the tank appears clean and clear while the water quality is degrading.

All the above is why I do not conventionall pack any canisters anymore. I segrgate bio and mech into separate units and rinse the mech frequently along with the prefilters on the bio. The biomedium itself, if chosen to be self-cleaning, should only rarely need any rinse. If bio does need rinsing, the use of removed tank water is conservative, as Cearbhaill suggests.

http://www.aaquaria.com/aquasource/cannister.shtml