Do you turn off Canister filter during WC?

[DiscusBR]

The main reason I ask is concern for the benefficial bacteria that live in the canister media (in my case, an Eheim 2217). Will the bacteria be fine be without water flow for, say, 20 minutes?

Thanks,

Mauro

[Elite Aquaria]

Yes

[DiscusBR]

Thanks, Dan.

Does anyone know for how long can one switch off the canister without worring that the bacteria will be affencted?

[Elite Aquaria]

I have shipped sponge filters to my customers overnight and they have been fine.

[ericatdallas]

Thanks, Dan.

Does anyone know for how long can one switch off the canister without worring that the bacteria will be affencted?

It depends on how much oxygen is in there... once oxygen is depleted, anaerobic bacteria start to take over. I've left it off overnight with no "apparent" problems before though.

[aalbina]

Yes for the 20 minutes it takes to do 75 to 80%. I have to turn it off because I drop the water lower than the intake. Never had a problem with any impact on the canister bio filter.

Adam

[DiscusBR]

Thank you everybody. I am going to do my first major WC, with water going below the filter's intake, and was wondering how to proceed. This site has, again, clarified my beginner's doubts.

[DiscusBR]

WAIT! I have another question. When I turn off the filter I need to close all valves in the intake and outake tubes, to prevent air from getting in, right?

[laborelch]

I have 2 Eheims 2026 on my 95g and usually close the valves right before unplugging the filters. After the water change, I plug the filters back in, then open the valves within seconds - filters kick on instantly and I don't have to deal with priming/siphoning.
The warranty might say to unplug first and then to close the valves in order to ensure the motor doesn't burn out :-) but that always left me priming and siphoning....

[ericatdallas]

I have fluvals and I close the valves (pull the tab up) before unplugging (I have it on a surge protector, so I switch it off). Then the opposite steps --- switch on, open valves. So same as laborelch.

[DonMD]

During a power outage, my canister filters were turned off for about 18 hours. When I got them going again, everything was fine. No spike in ammonia or nitrites. If I turn them off during a WC, I never bother closing valves. As long as the return hose to the tank is full of water, it usually starts up without any priming. You'll just have to experiment. Good luck!

[3dees]

I need to turn off my xp3 as it will stop after the water goes down 6" and I'll have to prime it which is a pita. the Ehiem I leave running. when I change the floss I just un plug them. never had a problem.

[Darrell Ward]

The main reason I ask is concern for the benefficial bacteria that live in the canister media (in my case, an Eheim 2217). Will the bacteria be fine be without water flow for, say, 20 minutes?

Thanks,

Mauro

No, I don't turn it off not unless I'm cleaning it. Bacteria could live in your canister a couple of days, maybe longer, before they run out of oxygen. 20 minutes is nothing. The only canister I run these days, is an Ocean Clear 354 bead filter, which I take apart and rinse out about twice a year. This is all that's needed, since it only contains plastic beads. Priming these filters is no big deal. They have a purge "valve", really a thumbscrew that you can open to release the trapped air. Works every time. Like Don said, if your return lines are full and under water, it should start right back up anyway.

[Jhhnn]

I don't close the valves on my Cascade canisters when changing water, but I do shut off the pumps. The canisters are on the floor, well below tank level. Water is trapped in the hoses as tank level goes down below the intake during water changes When re-started, they just burp some air out the discharge. Sometimes I can hear air bubbles being whipped around in the pumps after a water change, so I kinda burp the filters- off for a few seconds to allow the air to escape into the discharge hoses, then back on to push the air out. A couple of cycles of that & they're back to normal.

If I forget to shut off the pumps, then I have to re-prime, which is just some mad pumping of the big primer buttons on top of the filters, but I'd rather not...

[DiscusBR]

Thank you all. Amazing forum. I never stop learning...