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Best media for external filter.

G

Genahanney

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7 Aug 2023
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15
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Russia
Hi!
What do you guess is the best media for the Eheim 2217 filter in a 200 l aquarium with plants and medium-filled fish?
1. What is the best media to oxidize ammonium?
2. Why do you think that? Is preferably on a real example.
3. If you have a real example of using one media first, and then you chenge it with another and it got better (or worse) - this is the best.
4. The larger the surface area, the more bacteria - right?
5. The larger the bacteria, the more efficency to oxidize ammonium - right?
6. The larger the surface area, the more sludge?
Thanks a lot!
 
On 3 I don't have a direct example but one that applies. When I upgraded from one ex1200 to two I split the media I had between the two and then added mostly BioHome Ultimate media. I had fully bought into the hype. My filtration capacity didn't even close to double. Whilst the flow in the tank increased significantly which came with its own improvements the tank, even after years with both filters running, can still show wobbles in the amount of ammonia processed. It's only sunk cost fallacy that stops me throwing it all out and putting in sponges. (Also I mostly have 10PPI sponge lying around and I'd really want 25-30PPI)

I fully believe medium sponge is the best media I've ever used. Easy to clean, easy to tell when to replace, great at growing bacteria all over the media and doesn't reduce flow too much. I haven't used "pot scrubbers" but I can imagine that would be very good media as well.

The Biggest thing I ever did to improve my filter processing capacity was to put intake sponges on the filters. Organic matter being cleaned out by hand, rather than using up oxygen in the filter decomposing on the first sponge, makes a huge difference to the stability of the biological environment within the filter. With intake sponges I can go 6 months or more without cleaning the filters. Without intake sponges it was more like 6 weeks.
 
Hi all,
LightingBamboozled said:
The Biggest thing I ever did to improve my filter processing capacity was to put intake sponges on the filters. Organic matter being cleaned out by hand, rather than using up oxygen in the filter decomposing on the first sponge, makes a huge difference to the stability of the biological environment within the filter. With intake sponges I can go 6 months or more without cleaning the filters. Without intake sponges it was more like 6 weeks.
Click to expand...
Very true, I'm honestly amazed that everybody <"doesn't use a sponge on the filter intake">.

I use really <"substantial foam blocks">, but Eheim etc. make a prefilter <"EHEIM Vorfilter">Item number: 4004320 .
141105011149_600x600.jpg

and OASE have an internal prefilter <"Biomaster Prefilter Foams">.

cheers Darrel
 
I also use a DIY foam prefilter. Ironically I picked up that tip from one of Mr BioHome's videos #irony. Might have to look into the Eheim one. (quite a lot of money for some sponge and plastic)

_Maq_ said:
3. Any media or no media makes no difference.
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'...or no media...' - I'm a real newbie but this seems pretty surprising. Really no media?
 
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LFNfan said:
Really no media?
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Well, see my signature: No biological filtration. I only make water move by internal pumps.
Biofiltration occurs mainly within the substrate, microbes have a plenty of area to live there and do their jobs. As long as the uppermost layer of substrate remains oxygenated. Also, plants pump oxygen in their rhizospheres and microbes and plants in good harmony do a great job there. That's the natural way.
External, or more broadly, additional biofilters are indeed important in heavily stocked environments, like commercial fisheries, or tanks full of juveniles without substrate and decorations. Also, if you keep big fish like cichlids which disturb the substrate. But for a tank focused on plants with moderate stock of small fish, additional biofiltration is not a must.
Another question is mechanical filtration. I don't use it neither and my water remains clear. Still, sponges are recommendable because they combine basic mechanical and biological filtration.

In short, I do not exhort people to follow my example and get rid of filtration altogether. I just maintain that we cannot "instruct" our microbes to move from the substrate to our filters, we cannot tell what media and flow rate would fit them best, and therefore much of the talk about "best media" is a waste of time. Let's approach the question from the other side: we provide microbes with some kind of substrate, and we may rest assured it will be colonized by microbes which like given conditions and do the job we expect.
A safe bet? Ordinary sponges. In any case, keep the water moving, and in times of need (summer heats etc.) be ready to add some way of aeration (I prefer venturi).
 
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Agree with much of this regarding lack of evidence of efficacy of biomedia, but isn't one thing that a decent size external filter provides is water volume which would presumably add to the stability of any smaller size set-up.
 
_Maq_ said:
Biofiltration occurs mainly within the substrate, microbes have a plenty of area to live there and do their jobs. As long as the uppermost layer of substrate remains oxygenated. Also, plants pump oxygen in their rhizospheres and microbes and plants in good harmony do a great job there. That's the natural way.
Click to expand...
Right - substrate 👍

I don't have sand but I have fine gravel (1 - 1.5mm) and it's about 1 inch deep across most of the tank (a bit more in some places a bit less in others). After I rescaped recently and moved a lot of the substrate around @bazz suggested more frequent water changes for a few weeks. Makes sense given how you explain the link between biofiltration capacity and substrate.
 
Hi all,
_Maq_ said:
Let's approach the question from the other side: we provide microbes with some kind of substrate, and we may rest assured it will be colonized by microbes which like given conditions and do the job we expect.
A safe bet? Ordinary sponges. In any case, keep the water moving, and in times of need (summer heats etc.) be ready to add some way of aeration (I prefer venturi).
Click to expand...
I think that is the take home message from <"wastewater treatment in aquaculture"> etc.

They either use <"Kaldnes K1" type floating cell media">, or just rely on the microbes <"forming microbial flocs">.

Nitrification is <"really all about oxygen"> and <"then the time"> to develop a diverse and robust microbial assemblage <"Correspondence with Dr Ryan Newton - School of Freshwater Sciences, University of Wisconsin—Milwaukee">, which are the facts that the <"purveyors of Biohome etc"> don't want you to know, because they can't sell <"you oxygen"> or <"time">.

I have a very jaundiced view of our industry <"This whole anaerobic filtration thing is getting out of hand!">.

cheers Darrel
 
LFNfan said:
I don't have sand but I have fine gravel (1 - 1.5mm)
Click to expand...
Please, help a poor foreigner: What is the difference between "sand" and "gravel" of the size you indicated?
 
Malarky said:
but isn't one thing that a decent size external filter provides is water volume which would presumably add to the stability of any smaller size set-up.
Click to expand...
True. I'm actually contemplating such a "pledge" effect of a filter.
An example: This summer, temperature in my tanks quite suddenly rose by 5 degrees and several of my tanks lost stability - algae appeared, green bloom, some plants suffered, several species gone altogether. A disaster of medium dimensions, I'd say. I wonder whether the effects would be milder if there were an additional space like a canister filter with different conditions (compared with the tank itself) and different microbial assemblage. Maybe? Who knows?
Yet I can imagine a reverse situation as well. Either due power break, or similar temperature change, it may happen that it's the filter which loses stability. It can quickly turn into a source of reduced compounds like ammonia, hydrogen sulfide, and many more. A disaster of more than medium dimensions may be the result.
It's hard to make definitive assessment.
LFNfan said:
I call it gravel because 'fine gravel' was written on the bag
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In my country, vendors and customers often discriminate between "řiční písek" and "kopaný písek". The first is taken from a river bed, either current or (more often) ancient. The latter is mined from soil. The difference is supposed to be in the sharpness of edges. The latter, sharper, is preferred in construction, while aquarium hobbyists prefer the "river sand".
Is it possible that above described differences refer to "gravel" and "sand"?
 
_Maq_ said:
Please, help a poor foreigner: What is the difference between "sand" and "gravel" of the size you indicated?
Click to expand...
The difference between gravel and sand is the size of the grain. Gravel is coarser than sand. But at 1-1.5mm, IMO it should be called sand (perhaps coarse sand), not gravel.
For more information there is wiki: Gravel - Wikipedia
 
1.0 - 2.0mm major diameter particle size is definitely coarse sand and not gravel. Fine Gravel I would usually expect 2.0-4.0mm grain size. If none of the grains are above 2.0mm then I would have thought you'd be obliged to call it sand.
 
_Maq_ said:
Is it possible that above described differences refer to "gravel" and "sand"?
Click to expand...
Similar distinction here with 'builders sand' (smoother, from rivers) and 'sharp sand' (not sure where this is sourced). Actually both are used in construction ('builders sand' for mortaring and sharp sand for cement).

My aquarium 'gravel' has a bigger grain size than builders sand and also sharp sand, but much closer in size to the latter and much closer in smoothness to the former.
 
_Maq_ said:
But for a tank focused on plants with moderate stock of small fish, additional biofiltration is not a must.
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Hi! I think so too, but why Amano recommended full canister filter filled by biological media? What do you guess about this?
 
Genahanney said:
Hi! I think so too, but why Amano recommended full canister filter filled by biological media? What do you guess about this?
Click to expand...
Sponges= good biological media and can also do mechanical filtration. What's not to like?
So putting sponges into your filter is consistent with Amano's recommendation.


As Clive as pointed out, this is also good biological media:
12714486374_5b673bb9a1_z-jpg.jpg
 
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