The Planted Tank Forum banner

How to know when your canister filter needs cleaning.

3013 Views 23 Replies 16 Participants Last post by  Green_Flash
I did a water change today after being on business travel for 3 weeks.

Turned back on my C-360 and got a massive cloud of black gunk out of it. Looked like black smoke bubbling out. I normally go about six months between cleanings and normally see a reduced flow when it's time to clean them.

This is a first for me. Anyone else have this happen to them?
1 - 20 of 24 Posts
I found that in my tanks I need to clean the canisters every 2-3 months for optimal performance. Once your filters get all "gunked" up they are no longer running the way they should and the performance drops drastically. If cleaning is done on a regular schedule then it doesn't take too long to get a filter clean again...it generally takes me less than 15 minutes for the Eheim to be sparkling.
I back flush my Eheims once a week and clean them bi-weekly. I've read that keeping the tank and filters clean can help avoid algae problems. You need to be careful though when cleaning the media not to clean out too much of the bacteria colony.
If this is the first time you've seen the cloud and assuming it is not the first time you've turned off your filter for a WC then why was it different this time? Did you move or bump the filter?
Actually, I've got two filters running so if I wanted too I could bleach sterilize one filter when I clean it out without issue. Major reason why two filters on large tanks are better than one. I've also got a large plant to fish ratio that suck up the nitrogen quicklt.

First time this has happened in 10 years with canisters. Always unplug the filters and heaters during a water change.

Kind if reminded me if the video's of smoker vents in the ocean.

Schedule out maintenance, my travel scedule makes that impossible. Set an note on my calender to have it go off while I'm in some random country. I just got back from Uzbekistan, Jordan, and Turkey. I'm working on booking my next 3 trips today. My tanks are designed for this type of schedule so it's worked well for several years.
there is zero reason to sterilize a filter.

the only thing a filter needs done is to remove any thick build up in there that is slowing down the water flow and rinsing the media real quick in tank water in a bucket.

sterilizing the filter will probably just result in a mini cycle.
I'm thinking you mentioned bleaching as a drastic thing that COULD be done, rather than what you do?
For me, my canisters are watched for reduced flow. Over time, I've found they do quite well on a more or less, two month "schedule". One big advantage to canisters is that the flow will let you know when they are getting full. HOB just bypass the water, canisters do not. As the flow slowly goes down, my need to clean goes up. At some point, it gets done. Better sooner but sometimes later. Sounds like that might fit your travels.
On the gunk coming out, I'm guessing there was maybe more work done around the tubing that maybe broke some of the grung inside loose? I often get that if I rearrange the tubes. Lots of minerals gather on the tube walls and breaks off. Does come out like a smokey cloud but it is still just stuff in the water, just out where I see it. It is reaborbed right away and goes back where I can't see it!
Wait did I just see the words "bleach" and "filter" in the same sentence :help:
I usually perform maintenance on my filter once a month and that's only because I have tons of plants and do trimming like every other week and don't scoop out the trimmings. What I do is siphon tank water into a bucket and place my bio media in that bucket then take all my mechanical media and the canister itself and spray that down outside after that I I put everything back together and fill the canister with the water my media was chillin in. Literally takes me about 15-20 mins :icon_smil
To help with the "cloud of gunk" put some panty hose over the output before turning the filter on. It will catch the gunk,
6 months? Wow. Since you have 2 filters, I'd alternate and do one each month.
There is usually some sediment that comes out after a filter cleaning. Its just the stuff coming from the lines. Don't bleach your filter horrible idea lol.

-Chris
Monthly, with a media change based on the manufactorer's recommendation. I follow up with my mouthingly water change.
There is usually some sediment that comes out after a filter cleaning. Its just the stuff coming from the lines. Don't bleach your filter horrible idea lol.

-Chris
This. If the gunk came out when it was turned back on then it was likely just some crud from the lines getting knocked lose after stopping/starting water flow.

I clean the lines on my filters when I can't see into/through them anymore (green eheim tubing).
LOL pretty funny you guys. I've been doing this routine of 6 month filter cleaning for years now. This black smoke is the first time this has ever happened. Even when I kept goldfish and had to do monthly cleanings this never happened. The filters just got clogged in a few weeks. I found it funny and was wondering if anyone else has had the same thing.

Yes, I've actually bleached filters before. Many times actually. Normally after running some fish through QT and losing a few. Recipe was something like this.

One 10 gallion QT tank & an HOB filter running.
Add 1 cup of bleach.
Wait 2-3 hours until sparkly.
Rinse & Repeat & Repeat & Repeat & Repeat. Rinse don't fill and dump due to dilution calculations.

Great way to get rid of misc nasties.

I like running two filters cause I can clean them out to my heart's content. Never had to bleach them yet but I may. I generally run hot water through everything to get all of the crud out. As long as stagger the cleanings 1 month apart there's never any issues.

Spent a few boring years as a microbiologist in the lab. Not my most exciting job but I learned something about microbes. In this case if I kill of 50% of all of the microbes in the tank it will be replaced in around 20 hours. Never any chance of a build up of NH3 to be dangerous.
See less See more
I did a water change today after being on business travel for 3 weeks.

Turned back on my C-360 and got a massive cloud of black gunk out of it. Looked like black smoke bubbling out. I normally go about six months between cleanings and normally see a reduced flow when it's time to clean them.

This is a first for me. Anyone else have this happen to them?

I remove the media and dump the dirty water out of the canister with EVERY water change. I rinse the media once a month.



But how often are you cleaning your hoses?
i change them out with new hoses about twice a year.
I run 2 canister filters too and I alternate in cleaning them so I know I've got a good working bacteria colony undisturbed in one. What blew out of your filter was likely just the detritus of colony and though it didn't look good was of no harm to your tank.
I agree with the folks above in that this is not a good reason to decimate your bacteria colony with bleach. Just give the media a good flush, wipe out the inside of your canister, and brush out your lines. Don't use bleach because one of these times you may leave too much of it behind and that will be the end of your tank life.
It's like a game of telephone on this thread... pretty funny. Thanks for the laughs.
But how often are you cleaning your hoses?
I get brown biofilm that comes loose and shoots out of my hoses just about every time I clean them.

I clean my canisters usually every 2-3 months. I replace the mechanical media, put in a fresh bag of Purigen if needed, and squeeze out the sponges in dechlorinated or tank water.

The way I see it, there's no good reason to leave all that biosludge inside the aquarium system to keep messing with water parameters when the whole point of a filter is to REMOVE it from the system (with less effort on our end vs having to go through and manually siphon it out of the main tank). Clean water for the livestock is my primary concern there.

If I had a cloud of black sludge shooting out of my filter, I'd personally take that as a sign that I needed to clean my filter more often.
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top