Why we clean media?

Tom Michael

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I have been doing my usual, putting off cleaning my filter media and was wondering what the logic is with doing so?

I understand this must be completed if affecting flow, however beyond this why?

Build up of organics, well I water change and isn’t there a tremendous buildup of organics in the soil?!
 

Nick potts

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The filter is going to be the place where most debris and muck is going to accumulate (it's what they are designed to do)

In time all the muck is going to start clogging up the filter media, apart from flow reduction it can also reduce oxygen levels which are very important to the bacteria.

Filters don't usually need to be cleaned all that often, i know some people go 6+ months without cleaning
 

dw1305

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Hi all,
The filter is going to be the place where most debris and muck is going to accumulate (it's what they are designed to do)
That is where it normally <"starts to unravel">.
In time all the muck is going to start clogging up the filter media, apart from flow reduction it can also reduce oxygen levels
That is the real issue.
I have been doing my usual, putting off cleaning my filter media and was wondering what the logic is with doing so? I understand this must be completed if affecting flow, however beyond this why?
There is an <"optimal depth for biofloc"> on the filter media.

Quite what that depth is depends on whether you want <"anaerobic denitrification"> to occur or not. I'm not keen on <"anaerobic denitrification in a canister filter"> so I never want a thick and sticky biofilm, like the one that would develop if you didn't have plants, kept messy fish, didn't have a pre-filter etc.

If you have high levels of dissolved oxygen in the filter you probably won't ever get a lot of biofloc forming.

cheers Darrel
 

lilirose

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I use sponge filters (you probably have some sponge in yours, even if it's a cannister?). I normally clean them every couple of months, but on one of my shrimp tanks I just forgot about it. After about nine months the water started to look murky, and I couldn't work out why. It got worse and worse as time went on and I was thinking I would have to break down the entire tank as the water was so cloudy you could hardly see a thing.

Then it hit me- I had not serviced that filter since installing it in the tank. I took it out and cleaned it well- it was so dirty that I don't think it was picking up anything from the tank at all. I put it back, and now my shrimp tank is crystal clear. I've set up reminders on Google Calendar so I don't risk forgetting again.

It's better to clean frequently rather than to wait as long as I did and almost crash a tank.
 

Tom Michael

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Thanks all, okay I get it, remove as much of the fish/plant waste as possible, which naturally accumulates in the canister. Well, know what I’m doing this weekend!
 

dw1305

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Hi all,
I use sponge filters....... After about nine months the water started to look murky
Sponge is slightly different when the sponge isn't in a canister, because it is in contact with the oxygen rich water and can never become totally anaerobic. Stephan Tanner talks about this in <"Aquarium Biofiltration">. Having said that nine months is quite a long time, and I'd definitely have a look at them every month or so.

cheers Darrel
 
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I think that’s one disadvantage of the canister, you can’t see the buildup as easily so it’s easy to put off cleaning it. I love canisters but my current tank is the first sumped design I’ve had. If I could do it over I’d get a smaller sump, I didn’t account for the limited space I would have to work in it so servicing mine is literally a pain in my neck lol. But with a sump you can see that detritus and decaying plant matter very easily so the OCD kicks in to clean it for me. But I also keep some snails down there to help with the build up, can’t do that with a canister!
 

zozo

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IMHO if it's the flow you're after, then clean a canister when the flow is reduced below the desired threshold. :)

Or go for a correct sized trickle sump. :p This simply can't reduce and can do months if not years without cleaning. 💪
 

Luketendo

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As others said especially the sponge at the bottom of my Eheim classic builds a lot of brown muck, and even the water surrounding the seachem matrix etc accumulates goes dark brown when I remove the matrix. Can't think that it is beneficial so worth removing.
 

tiger15

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To understand why the media need to be clean frequently, we have to understand there are two broad types of micros that colonize the media.

Heterotrophic micros include not just heterotrophic bacteria that utilize dissolved carbonaceous material as their food source, but also a range of heterotrophic protozoa, worms, rotifers and even snails that feed on organic scums. When we have a bacterial bloom, the bacteria are predominately heterotrophic bacteria.

Autotrophic bacteria such as Nitrosomonos and Nitrospira will both grow and colonize the biofilter and utilize ammonia and nitrite released by the heterotrophites as food source. Autotrophic bacteria are relatively slow growing. Heterotrophic bacteria grow about 5 times faster and will out compete the other two types for space if food is available. Since the purpose of a biofilter is to remove toxic ammonia and nitrite, having over population of the heterotrophites in the media can out compete autotrophic bacteria for oxygen and living space thereby reducing their efficency. There is also danger in power outage that the heterotrophites would use up all the oxygen leading to biological crash. So there is benefit to clean the media frequently to get rid of organic scums and heterotrophites to make room for autotrophites.
 

chrisfraser05

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I do believe that alot of keepers long term success, especially fighting algae, comes down to lack of attention to cleaning filters.

Things aren't looking good, ammonia readings are still good so it can't be the filter, so we struggle to figure out what it is.


We don't realise that a poorly maintained filter is worse than having no filter at all (in a planted tank at least where plants will consume the ammonia).
 

zozo

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I have such a small tank setup up as paludarium, it has mainly emerged plants and the soil is partially above the waterline.



It only has a small HOB with no media in it to create some turnover. The hob spills the water and the muck it pumps up over the emerged substrate behind the huge Cyprus plant at the back RH corner. And this plant is growing like mad gets all the manure it needs and currently almost 2 meters tall. :) With an enormous amount of liverwort growing at its base.

The cherries and dwarf corries in it are really happy with an average weekly 50% (20litres) water change and all are healthy and it runs for over a year now.

The tank is its own open-air trickle sump filter like that... Works a charm. :D

The idea behind it was this, a perforated pipe bellow in the substrate with a 90°vertical bend.


In the pipe, the water level equals with that from the tank and the HOB pulls the water from the pipe and spill it on the substrate. Semi under gravel and over gravel filtering...


💪 There is nothing to clean...
 
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Well if I don't cleanmy sponges in my sump from time to time it clogs up so much that the flow restricts and the water would rise in the first chambers..

I can see having clogged up media in a cannister restrict your in tank flow and co2 distribution getting your plants to decay and make more bioload for your filter to cope with.
 

dw1305

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Hi all,
We don't realise that a poorly maintained filter is worse than having no filter at all (in a planted tank at least where plants will consume the ammonia).
That is right, the filter is only part of a <"much wider nitrification system">. <"Failure of one component"> is much less important in a planted tank, because you have extra nitrification capacity and <"negative feedback loops">.
The tank is its own open-air trickle sump filter like that... Works a charm
Trickle filters are the Rolls-Royce of filters for nitrification, they have a huge gas exchange surface area. You also have a shallow tank with plants with the <"aerial advantage">.
There is nothing to clean.
It is the oxygen that makes the difference, a few people have <"found this"> and been worried, but I look on <"complete oxidation as a good thing">.

cheers Darrel
 

zozo

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Well if I don't cleanmy sponges in my sump from time to time it clogs up so much that the flow restricts and the water would rise in the first chambers..

I have a sump to for another tank... But I don't experience this, I can leave it uncleaned for months without clogging.
My guess is it's the way the media is build up and how the sumps is sized. Mine is rather oversized 25% of the main tank. My overflow runs into a chamber without any media, this collects some heavy sinking debris. Then the water overflows a baffle with trickle pipes and trickles on a rather coarse sponge pad. Then the water trickles down through some ceramic pipes mixed with alfagrog, then it runs through a fine polishing sponge. And that's all to it... Nothing ever clogs up, the water must be relatively clean and free of debris before it goes through the polishing part.

The most of the debris that is collected is never submerged, I guess this also is a huge advantage and it breaks down faster and differently as if it was submerged. The bio media part i have only cleaned once in 4 years time. ALso because I felt like it, that was the only reason.

Anyway, sometimes i clean the polishing sponge only because I just feel it is time to do so. But actually don't know if I had to or should because it yet never affected the water levels in the sump.
 
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I have a sump to for another tank... But I don't experience this, I can leave it uncleaned for months without clogging.
I'm aware of your sump, we have discussed it in my threat of my sump build..

I must say it took a few months to that point the sump was working just fine noticed a raise in the water level in the first part if I didn't clean it I think it would overflow to the last part of the sump and not in the correct way.. It was the medium coarsed sponge that got clogged when I cleaned it took a while to get it out.. I don't think my sump is small compared to the size of my tank.. it's around 1/3 of the volume..
 

Oldguy

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I have been doing my usual, putting off cleaning my filter media and was wondering what the logic is with doing so?

Water flow and oxygen levels. I use my canister filter for flow and to power other devices. It has a huge pre-filter, the gravel substrate of the tank, the canister works the uplift. I do not like sponge filters they clog up with microbial growth and have replaced mine with fired clay balls from hydroponics which are cheap and enable a high flow and decent dissolved oxygen levels to be maintained. I clean the canister out about once a year if I remember.
The canister output is split between a good UV unit (main flow) and the lesser flow feeds a ten gallon net trickle filter which has a spray head for a mist distribution onto again, clay balls. The unit is mounted above the level of the display tank.

The gravel substrate is siphon cleaned about once a month as part of general maintenance. Some parts are not cleaned that well because of plants.

It is the oxygen that makes the difference

With a good dissolved oxygen content you can smell the difference.

Trickle filters are the Rolls-Royce of filters for nitrification, they have a huge gas exchange surface area.

A tad wasteful on injected carbon dioxide but a small price to pay for a healthy bio-system. Would not be without mine, again a wholesome smell.

CO2 diffusion and flow distribution is via a dedicated in tank power head with high flow wire mesh intake screens.

Always keep an eye on the return flow rate, its a simple indicator of required maintenance.
 

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