# Canister Media in Planted Tank



## jameson_uk (27 Nov 2016)

When I started I got plants because they looked nice and they were "good for fish".  I never really considered the implications of plants on the whole bio system so just set up the canister I inherited with a standard setup (I.e. with an emphasis on biological filtration)

I have since added a prefilter but I am wondering whether I have the right balance of media.

I have an eheim 2217 (classic 600) with the eheim prefilter; which has two sponges (not sure of PPI but is  it really fine).

This goes into the canister which has a layer of efimech then a coarse (blue) sponge, then a huge amount of substrat pro then a fine sponge and a bag of Purigen.

Should I be looking to reduce the amount of biological filtration and up the mechanical?


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## dw1305 (27 Nov 2016)

Hi all,





jameson_uk said:


> Should I be looking to reduce the amount of biological filtration and up the mechanical?


No, basically the mechanical filtration is carried out by the Eheim pre-filter. I clean this every week (or fortnightly), just by giving it a good swish under the cold tap, if you don't squeeze the sponges they last a long time (~ 10 years).

I don't have any fine media in the filter, the blue coarse coarse sponge (PPI10) is fine, and so are the mech and coco-pops. I'm not a purigen user, but if I was I would have it at the top by the outlet. 

If you don't have any fine sponge in the filter body you should be able to leave the filter body undisturbed for a reasonable amount of time (at least three months) and probably longer.

If it was my filter I'd just have the coarse sponge on the bottom grid, with the substrat pro on top.

cheers Darrel


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## sciencefiction (28 Nov 2016)

Filters in planted tanks are for redundancy. If the plants go wrong for one or another reason, the filter picks up the pieces keeping the tank happy. The minimum benefit is you'll run in a lot less algae issues with decent filtration in a planted tank. 

In a planted tank everything acts as media for bacteria, the substrate, plant roots and leaves, etc...So although plants spend less energy when consuming ammoniacal nitrogen instead of nitrates, you can't control the rate of bacterial population and the nitrogen cycle. Decent filtration also ensures good flow around.


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## jameson_uk (6 Jan 2017)

I have been having some noise issues (https://www.ukaps.org/forum/threads/eheim-classic-noise-new-impeller.48306) so have had the filter open a few times recently.

Each time I have taken the opportunity to rinse the white fine sponge which I have been looking to remove; each time it has been filthy and there has been a huge amount in there to rinse out.   Presumably if i remove the sponge then all of this will end up back in the tank but is this an issue?   Do I actually want this to go back into the tank and get processed back through the pre-filter and then other media rather than just having it sat on the white sponge?

Is the fact it is manky a concern?   Should there be this level of dirt moving round?   I need to replace the impeller (which I should get time this weekend) so can take a video of how dirty it is since I last cleaned it (Thursday this week)


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## sciencefiction (6 Jan 2017)

Any type of media that has the potential to clog your filter should be removed. If you are not concerned about aesthetics, why not put a coarse sponge block on your intake...Rinse that instead as often as you like.


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## jameson_uk (6 Jan 2017)

sciencefiction said:


> Any type of media that has the potential to clog your filter should be removed. If you are not concerned about aesthetics, why not put a coarse sponge block on your intake...Rinse that instead as often as you like.


I already have coarse sponges on the pre-filter which get rinsed weekly which is what has made me wonder about the amount of crap at what is effectively the filter output


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## limz_777 (7 Jan 2017)

sciencefiction said:


> Filters in planted tanks are for redundancy. If the plants go wrong for one or another reason, the filter picks up the pieces keeping the tank happy. The minimum benefit is you'll run in a lot less algae issues with decent filtration in a planted tank.
> 
> In a planted tank everything acts as media for bacteria, the substrate, plant roots and leaves, etc...So although plants spend less energy when consuming ammoniacal nitrogen instead of nitrates, you can't control the rate of bacterial population and the nitrogen cycle. Decent filtration also ensures good flow around.



agreed , always wonder why ada handbook suggest removing the sponges after some time and using the filter as a bio-filter


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## jameson_uk (23 Aug 2017)

I have upped cleaning the pre-filter sponges to twice a week and they are always pretty manky.

Came across https://www.allpondsolutions.co.uk/aquarium/filters/external/ef-booster-supplimentary-canister/ which I guess wouldn't be that great as a pre-filter (I believe they say it will reduce flow by 40%) but was wondering whether making use of some pipework and a pump I have lying around would make this worth a go for £15 (and would add some redundancy)

Also I know @dw1305 has mentioned about not using a canister as a syphon on a planted tank.  Would it be worth adjusting the contents of the canister?  Might the volume of bio media lead to it out competing the plants or become anerobic?


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## dw1305 (24 Aug 2017)

Hi all, 





jameson_uk said:


> Came across https://www.allpondsolutions.co.uk/aquarium/filters/external/ef-booster-supplimentary-canister/ which I guess wouldn't be that great as a pre-filter (I believe they say it will reduce flow by 40%) but was wondering whether making use of some pipework and a pump I have lying around would make this worth a go for £15 (and would add some redundancy)


It should work OK. I'd take out the fine sponge (you don't need to replace it with anything).





jameson_uk said:


> Would it be worth adjusting the contents of the canister? Might the volume of bio media lead to it out competing the plants


I don't think that plants and the filter are ever really in competition, mainly because it isn't really just plants, it is always plants/microbes. If you have more bio-load you get more plant growth, but plants are leaky structures and you get more microbial activity as well. Plants will take up the NO3 from microbial nitrification, so that fixed nitrogen hasn't been lost from the system.





jameson_uk said:


> or become anerobic?


That is the real worry for me, it is more unlikely in a planted tank (the water entering the filter is more fully oxygenated), but it is possible. If you don't have a planted tank, and you try and have simultaneous aerobic nitrification and anaerobic de-nitrification in the same filter, it is both very likely and will definitely kill all your fish.

Biofiltration capacity is very rarely restricted by the amount of media, it is oxygen availability that controls nitrification. You can deal with a <"huge bio-load"> (heavy ammonia loading) if you have enough oxygen. 

You can think of this  waste water treatment system (<"Effectiveness of Domestic Wastewater Treatment Using a Bio-Hedge Water Hyacinth Wetland System">) as analogous to what happens in a planted tank with a substrate.




cheers Darrel


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## jameson_uk (24 Aug 2017)

dw1305 said:


> I don't think that plants and the filter are ever really in competition, mainly because it isn't really just plants, it is always plants/microbes. If you have more bio-load you get more plant growth, but plants are leaky structures and you get more microbial activity as well. Plants will take up the NO3 from microbial nitrification, so that fixed nitrogen hasn't been lost from the system.


I was more thinking of the form of Nitrogen available.  Plants prefer ammonia as their source of Nitrogen (as it is easier for them to consume?)  But if you have a super efficient filter then might this convert all the ammonia to nitrate before the plants get a look in?



> That is the real worry for me, it is more unlikely in a planted tank (the water entering the filter is more fully oxygenated), but it is possible. If you don't have a planted tank, and you try and have simultaneous aerobic nitrification and anaerobic de-nitrification in the same filter, it is both very likely and will definitely kill all your fish.
> 
> Biofiltration capacity is very rarely restricted by the amount of media, it is oxygen availability that controls nitrification. You can deal with a <"huge bio-load"> (heavy ammonia loading) if you have enough oxygen.


Do people try for anerobic denitrification in their canisters?  I certainly only thought about the filter was there for ammonia => nitrite => nitrate and that was it.  Oxygen never even crossed my mind  ( which is why I did this place massively interesting and helpful  )

So presumably anerobic areas would be there only if all the oxygen was consumed whilst passing through the filter and the flow was then low enough to stay in the filter?


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## dw1305 (24 Aug 2017)

Hi all,





jameson_uk said:


> I was more thinking of the form of Nitrogen available. Plants prefer ammonia as their source of Nitrogen (as it is easier for them to consume?) But if you have a super efficient filter then might this convert all the ammonia to nitrate before the plants get a look in?


I think the preferred form of <"fixed nitrogen"> is ammonium NH4+, but nitrogen is always in short supply in the natural world, so plants are pretty efficient at taking it up in any form they can get. EI uses KNO3, so the form of nitrogen isn't a major issue. 





jameson_uk said:


> Do people try for anerobic denitrification in their canisters?......So presumably anaerobic areas would be there only if all the oxygen was consumed whilst passing through the filter and the flow was then low enough to stay in the filter?


You would be amazed. Have a look at the comments about Seachem Matrix (from Seachem) in <"Biological media....">.





jameson_uk said:


> I certainly only thought about the filter was there for ammonia => nitrite => nitrate and that was it. Oxygen never even crossed my mind


Most of the aquarium based literature is very focused on ammonia (NH3/NH4+), but for the biological oxidation to occur you need to add three oxygen atoms (you've gone from NH3 to NO3), which will tell you that the more ammonia you start with the more oxygen you need.

There are some really interesting  pages on biofiltration (in aquaculture) at <"http://biofilters.com/">, these really emphasis the importance of oxygen in dealing with high fish stocking rates.

cheers Darrel


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