# About biomedia plugging up



## niko (Jan 28, 2004)

So as we understand it now the biofilter in a planted tank (and not only) needs to have water flowing through it at a constant rate. Variations of the flow rate through the biofilter affect the microorganism populations - this could lead to a reduced removal of waste or to something as extreme as producing waste instead of removing it.

One way to ensure good constant flow through the biofilter is to use a pressure rated pump. Such pump will not reduce the flow through the media if the media plugs up (up to a certain level of course).The only commercial canister filter on the market that comes with such a pump is ADA's. And no, one does not have to have a pressure rated pump. But it will help you if you are lazy - it will prolong the time in which the filter can run ok even if it is dirty. If you really have to have one now go for Iwaki (the brand that ADA uses), or Blue Line or PanWorld (both made by the Iwaki engineer).

Another way to ensure constant flow through the media is to use media that is coarse enough so it does not get clogged easily. Basically it will let debries go through the filter and be dumped back into the tank. Most canister filters use mecanical filtration pads before the biomedia. These pads must be cleaned on a regular basis or they will obstruct the flow causing channeling and a flow pattern along the walls of the canister. The flow through the biomedia will be affected. ADA does not use any mechanical pads - just lava rock, which is a biological filtration media. Their lava rock is intentionally not very fine - to avoid clogging.

A better way to ensure good constant flow through the biofilter media would be to engineer the media in such a way that it does not clog by design. One such media is the Hamburger Mattenfilter, also sold under the name "Poret". There quite a few considerations in the build of a filter that seems very simple. The flow through the Poret needs to be slow and the foam's surface area needs to be large. Swisstropicals is the distributor for the real Poret foam in the US: 









ADA actually uses Poret in the initial stages of establishing the tank filtration ("Bio Cube"). According to them the Poret allows for fast growth of biofilter microorganisms but not as dense as the lava rock which they use in later stages.



























Another media designed not to clog is Matala. Note that the best use of the Matala pads is not as we all would think - stack them on top of each other like a sandwich. The best placement is vertical - alternating "walls" of coarse and finer pads. The water flow does not flow through the wide sides of the pads. It enters from the narrow sides. 









But many people use Matala stacked as a sandwich anyway. Note that one of the reasons to consider that not optimal is the need to disturb all the pads while cleaning the coarsest. The optimal biofilter should not be disturbed very often.

With the vertical arrangement and flow along the biomedia pads the water flow always has a few channels through which it flows with low resistance (the coarse pads) while it continues to penetrate the finer pads from both sides. The coarse pads accumulate the main bulk of the dirt. Meaning that the biofilter in the finer pads never experiences clogging, fluctuations in water flow and food supply. The flow through the Matala pads is much faster compared to the Poret. The exact combination of pads is up to you - there are 4 sizes (coarsness) to choose from. Note that the Matala material is engineered by a professional aquaculturist AND proven over the years in heavily stocked ponds:
http://www.matalausa.com/cat26.html

If nothing else - if you ever want to experiment consider rearranging the filter material in your canister similar to Matala. The idea being that the coarser sponges will allow for continous water flow along both sides of the finer sponges. A variation of that could be a cross between what Matala considers best and what ADA uses as a biofilter material - a setup made of coarse sponge "walls" with vertical layers of lava rock stuffed between them.


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## AquaBarren (Nov 6, 2009)

Niko,

Have you experimented with light, moving biomedia in a canister? I recall conversation on this forum about a filter loosely filled with a plastic material. I think it was often used in commercial applications. What I remember is that the loose packing and light material allowed it to move within the filter where it remained clean of debris. 

It sounded interesting. Had anyone ever tried a similar material in a conventional canister with, or without baskets? Seems like it should be achievable,..a canister filled with light material, packed loose enough to rattle around and clean itself. 

Just curious. Always looking for better or equal results with less maintenance.


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## niko (Jan 28, 2004)

No.

Someone from the club bought a bag of K1 (Kaldness). I gave him a big size canister filter that had a housing that was transparent enough to see the moving media. Don't know what happened after that.

K1 is not the only moving biofiltering biomedia. I suspect that one issue with all of them would be volume - how big does the filter need to be. 

The best place to see what really works is to look at the people that keep/breed expensive koi. Fish worth 10-50K each or more. These people surely know what works best.


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## AaronT (Apr 26, 2004)

Sounds like that Matala stuff might be good for a wet/dry filter as well. I just set one up a few days ago. I wonder which coarseness I would want to use?


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## Michael (Jul 20, 2010)

I did a little experimentation with Kaldness in HOB filters. It didn't work.

It is designed to be used with stong aeration which sets the media moving rapidly in a circular path up and down in the chamber. In a unidirectional flow as in HOB or cannister filters, the media collects at the highest point (because it has slight postive bouyancy) and does not move much. The movement is needed to encourage sloughing of parts of the biofilm, allowing different organisms to colonize different parts of the media.

Niko, now you have me wanting to retrofit my Eheim with Matala, and I haven't even changed out the coarse lava rock yet, LOL!


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## JustLikeAPill (Oct 9, 2006)

Just a note about Bio Rio being used as a biomedia... it also works excellently as mechanical filtration as well. 

IME, an equal amount (in liters) of bio rio on top of mechanical filtration (sponges) will collect way more particulate matter than the spongy material like blue eheim pads or the bio cube ADA sells. 

ADA reccomends all media to eventually be bio rio. They don't reccomend mechanical filtration, just biological filtration via bio-rio. The bio rio, however, IS the mechanical filtration as well as biological. 

It's amazing how much better it is than sponge-type material. IME, it works better than 45 PPI poret foam (meaning it collects more particulate matter than the foam, even when an equal amount is placed on top of it.)


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## niko (Jan 28, 2004)

I too will probably be filling one of my big Eheims with the Matala very soon.

But what Pill here wrote was interesting to me. I don't think ADA clearly says that BioRio is also a mechanical filter media. Yet they do suggest to rinse it on a regular basis.

The comparison of BioRio, sponges, and BioCube (Poret) was also very interesting. I'm starting to believe that one really needs to select the biomedia VERY carefully - it can have a profound effect on what is going on with the filter system. 

The lava rock that Michael and I use is much larger than ADA's BioRio. From what I see now, after a month of running both big Eheims in my 180 gal. (sand only tank, with 6.5x the water turnover per hour) is that the tiny partilces do not disappear magically because of the biofiltration. It takes a very small amount of mechanical filtration to polish the water, but without it the pretty large lava rock that I have does not eventually remove the tiny debries. I can only guess that ADA's finer lava rock will, like Pill here suggests. I'd be glad to give the finer lava rock a serious try but I don't know of a place other than ADA that sells that size lava rock. Pumice is what I'm really after because it can be found in different sizes. Any ideas?


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## JeffyFunk (Apr 6, 2006)

http://theaquaticgazette.com/2012/03/08/seachem-matrix/

This article discusses his experiences w/ Matrix in comparison to Bio Rio and Substrat Pro. Some highlights from the article specifically discussing Bio Rio:

"Besides using it in a cannister filter, Bio Rio presents challengers as its minute size requires filter bags. It is not easy to find small enough filter bags to fit properly into internal power filters or hang-on filters."

"Matrix also seems to clog less frequently than Substrat Pro or Bio Rio. Bio Rio clogs the fastest but that can be easily explained by its dense and packed nature. However, an advantage is that Bio Rio polishes water to a level unmatched by Substrat Pro or Matrix. If you intend to use Bio Rio, we highly recommend using Eheim's Classic cannister series, its ability to back-flush without removing Bio Rio from the cannister body is always very much appreciated and allows for easy regular maintenance."

I tried using lava rocks in my Eheim Classic Canister filter, but i don't think it had any real effect (although I'm also not sure how I would quantify it's effectiveness in the first place). Having Bio Rio in one of my Eheim Classic 2217 Canister Filters, i have to say that the small size of Bio Rio makes it very difficult (if not impossible) to compare to lava rocks - the mechanical filtration ability (as JustLikeAPill also states) of Bio Rio is pretty impressive. The only thing i don't like is the packaging size - the 2L package does not come anywhere close to filling up my Eheim 2217 Canister filter (I think i'd need 3 packages).

Perhaps the best thing for (most) canister filters is to combine the two filter media - Matrix for it's biological filtration capacity and Bio Rio for it's (additional) biological filtration capacity as well, but more so for it's mechanical filtration capacity. (Personally, I think some sort of mechanical filtration is necessary - how much is needed in comparison to biological filtration? I have no idea...) (??)


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## niko (Jan 28, 2004)

That was very interesting. Looks like each one of the top 3 medias needs to be used in a specific way. For example if BioRio gets plugged up quickly but polishes the water the best then you have to rinse it often. Apparently you don't have to rinse Matrix that often but you have to use additional mechanical filtration. 

In that overview Eheim's Substrat Pro seems to fall behind BioRio and Matrix. But as we now know the kind of biofiltration depends heavily on the flow rate. Eheim filters are designed for slow flow. Could be that by adjusting the flow Substrat Pro will perform as well or better than BioRio or Matrix. My point is - there are a lot of variables and it's hard to say that a single media is the best.

One thing that stood out to me in that article was the fact that BioRio plugs up fast. I didn't know that. To me rinsing BioRio was a bit of an overkill because I thought that ADA tanks are clean to start with. Turns out they are clean because BioRio acts as a serious mechanical filtration media. So you must clean it or you will affect the biofiltration in a bad way. The fast plug up of BioRio maybe an explanation for having to use a real pressure rated pump (Iwaki) on all ADA canisters. What we can't deny about using BioRio is its ultimate simplicity - one media has the role of both bio and mechanical filtration. I don't think I will advise not using mechanical filtration any more - I was mistaken that ADA did not use it, but it does. In a very simple and elegant way. If you keep up with the filter maintenance that is.

From quite a bit of reading about filtration lately I formed a solid opinion that mechanical filtration is indeed needed despite what I thought ADA did (only biofiltration). The most realiable source or two I found (whatever "reliable" means on the net) state that one needs to have both mechanical and biological filters. Preferably separate units. Apparently ADA follows the rule of having both mechanical + biofiltration, but one media does both filtrations and in one canister for elegance and simplicity's sake. That is not the best setup though - from what we know now it is best to not disturb the biomedia. It's pretty funny to say that ADA's is not the best filtration setup, but I think we will all agree how that can actually be so.

So if one is to use canisters it is definitely best to have one unit for biofiltration and another one for mechanical filtration. From what I see on koi pond videos the best setup would be if the mechanical filtration is before the biological (and not separate) - meaning that the mechanically filtered water feeds the biofilter unit. That brings us back to the original idea of this thread - it is important to know how fast the filtration media plug up. And the better engineered medias do not plug up easy - Matala, Poret, possibly Matrix.

I find this to be a great discussion. I don't have first hand observations on ADA's biomedia, Matrix, or Substrat Pro. That was very interesting! Thank you!


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## BruceF (Aug 5, 2011)

Autotrophic Nitrifying Bacteria Pre-Requisite: Surface Area and Flow Rates

Autotrophic bacteria do not actively seek out ammonia and nitrite. These compounds must be brought to them, which is why filtration flow rates and absence of filter bypass are of such importance. Enough water must be cycled through filter media in sufficient a time frame to prevent ammonia and nitrite concentrations from building up, standing in line (so to speak) to come into contact with the autotrophic nitrifying bacteria inhabiting the filter media. Autotrophic nitrifying bacteria do not exist in any measurable quantity in the water column itself. These bacteria exist (assuming it's an established tank and the autotrophs are not being out competed by heterotrophs) on every surface in the aquarium, including on the gravel/sand, on decorations, on plants, on those silly skeleton/treasure chest ornaments, on the walls of the tank, on the filter tubes, and especially, in the filter media. The more surface area that is available, the larger the colony of autotrophic nitrifying bacteria that can exist (and the better it is able to grow), which is why "surface area" is such an important consideration when purchasing bio-media. It's also why "bypass" is a significant concern when selecting a filter. Water that flows around filter media is not coming into contact with the autotrophic nitrifying bacteria, so the ammonia/nitrite that water contains will still exist as the water exits the filter. As this relates to Biowheel filters, flow rate is more important than surface area. Since there is no bypass with water coming into contact with a bio-wheel, and it exists in an oxygen rich environment, which allow the bacteria to be more efficient, it requires substantially less surface area than standard submerged filtration media. It is also feasible that water flowing over a biowheel becomes so saturated with oxygen that it degasses CO2, artifically (temporarily) inflating the pH, making the bacteria even more efficient.

Just as autotrophic bacteria compete with heterotrophic bacteria for oxygen, they also compete with heterotrophic bacteria for space. As with all living things, they (both types of bacteria) die. When they die they leave behind their corpse, and the corpse of these dead bacteria pile up on top of each other. The end result, they (along with other ditrius) fill in the pores of our filter media, reducing the available surface area. The benefit of these "pores" cannot be over rated. With them, a single Biomax type ceramic ring will possess a surface area equivalent to 1" of gravel in a 10-gallon tank. Without them, the same ring contains no more surface area than a single 1" rock in a 10-gallon tank. Dead bacteria are also an additional food source for living heterotrophic bacteria, increasing their populations. When heterotrophic bacteria consume the dead bacteria, the end result is the same as if they were consuming fish poo, with that result being ammonia (then nitrite, then nitrate). This process is also conducive to an environment more favorable to heterotrophic bacteria than autotrophic, which we do not want (not here anyway, more on that later). For these reasons, it is important that our biomedia is regularly cleaned. I take things to an extreme in this regard. Once per month, biomedia is removed from my canisters and rinsed well in tank water. I usually dump the media in a bucket of tank water and then stir the media around by hand. In addition, I will remove one tray worth of biomedia, replacing it with either new media or recycled media. The removed media is taken to the sink, rinsed well, and then boiled. Once clean, it is dried for several days on a towel and then placed into a zip lock bag for future reuse (when rotating out another tray of media.) For media that may be exceptionally dirty, I've even taken it a step further by soaking the media overnight in a solution containing APPlus+ Plastic Plant Cleaner before boiling it, making sure it is well rinsed before I boil it. I find that this returns ceramic media rings, such as Hagen and Fluval BioMax, to "like new" condition. When using APPlus+ Plastic Plant Cleaner to clean ceramic biomedia, I use it at the same strength identified on the bottle for cleaning plastic plants. Below is a photo of approximately 3 year old Hagen Biomax from one of my filters following this cleaning process (using APPlus+ Plastic Plant Cleaner). You can't tell a difference between it and brand new product.
http://www.oscarfish.com/article-home/water/71-autotrophic-bacteria-manifesto.html


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## JeffyFunk (Apr 6, 2006)

niko said:


> That was very interesting. Looks like each one of the top 3 medias needs to be used in a specific way. For example if BioRio gets plugged up quickly but polishes the water the best then you have to rinse it often. Apparently you don't have to rinse Matrix that often but you have to use additional mechanical filtration.
> 
> In that overview Eheim's Substrat Pro seems to fall behind BioRio and Matrix. But as we now know the kind of biofiltration depends heavily on the flow rate. Eheim filters are designed for slow flow. Could be that by adjusting the flow Substrat Pro will perform as well or better than BioRio or Matrix. My point is - there are a lot of variables and it's hard to say that a single media is the best.


I think this is a very interesting point, but not quite the conclusion i got from the article. I think filter media are made with compromises in terms of bio filtration and mechanical filtration capacity. In the case of Matrix, the particle sizes are very large and irregular; This means that they do not stack together tightly, resulting in little mechanical filtration (and no flow reduction). In the case of BioRio, the particle sizes are much smaller; This means that they do stack together tightly, resulting in much more mechanical filtration, but this results in filter media that clogs easily that needs to be cleaned regularly (and the use of Iwaki pumps in order to maintain flow rates). Imagine if the material used to make Matrix was made in the particle size & shape of BioRio! Now THAT would be awesome...


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## niko (Jan 28, 2004)

Bruce that was a very exciting link to very interesting information written in English!

I read the entire article about autotrophic bacteria (the ones that take Ammonia and convert it to Nitrate) but I was more i interested in what the "kmuda" guy has to say about heterotrophs (the bacteria that "eats" organics). Lo and behold he has a great article written about them too!
http://www.oscarfish.com/article-home/water/72-heterotrophic-bacteria.html

At the end of that article he gives a link to a thread discussing a very interesting actual experience with a big home made filter:
http://www.oscarfish.com/oscar-forum/viewtopic.php/f,5/t,81539/start,50/

The thread is about a filter that is actually capable of removing virutally all nitrates from a tank full of big and dirty fish (Oscars). That by itself is amazing but there is something else: On page 3 of the thread, on Nov 22, kmuda said something very interesting:
_"..After several years of experimentation I never achieved these dramatic results until I placed the 20 Micron filter in front of the deNitrate tower...."_

So here again we see that the quality of the mechanical filtration has a huge role! If you take the time to read both articles linked above + the thread about the safe "DeNitrate" filter you can't help but get really confused what to do with your filter to make it work the best. If you head doesn't hurt too much from all the confusing information you will see that there are three simple things to note:

1. You must use mechanical filtration before your biological filter.
2. The flow rate through the biofilter plays a huge role.
3. How to practically setup the "ideal" filter is not a simple question to answer but we would have a much better insight on the reasons for algae issues/plant health if we know what could be going on in the world of microorganisms that we call "a biofilter".

Going back to the world of planted tanks: Looking at ADA's canister filters and media setup:
1. The biomedia is also a mechanical filtration media.
2. The flow rate is not that large. And think of how slow the water must be flowing through all the rather small pieces of biomedia.
4. The upward flow inside the canister and canister design is like the original Eheims.
5. The "slow" flow is also like the the Eheim filters flow.
3. ADA pairs up certain canister sizes with certain range of tank volumes.


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## Michael (Jul 20, 2010)

"1. You must use mechanical filtration before your biological filter."

I've been doing this, but for other reasons, lol. In my tanks with Aquaclear filters, I have been putting a coarse sponge over the intake inside the tank, and nothing but lava rock in the media chamber. My reason is to prevent baby fish, snails, shrimp from being trapped in the filter. When the sponge gets dirty, I turn off the filter and clean it to restore flow.

For various reasons I have not been doing this on my Eheim, putting the sponge inside the cannister. These discussions always make me want to clean my filters, so when I broke down the Eheim yesterday I had a good look. The lava rock was clean even though it was below the sponge, but the sponge was severely clogged. So I put a sponge on the intake when I restarted the filter.

This is an easy, practical way to put the mechanical filtration before the biofiltration. BTW, when I opened the Eheim there were 3 baby bristlenose plecos and a whole colony of shrimp living in the filter!


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## JustLikeAPill (Oct 9, 2006)

Niko, you can buy Pumice in different sizes by the gallon on ebay. People use it as components of potting media for cacti and bonsai. It's really cheap.

This looks about right:

http://www.ebay.com/itm/Pumice-for-...ertilizer_Soil_Amendments&hash=item3a7b0d3116

Bio Rio isn't special pumice... it's got some oak charcoal and bacter 100 added but that's it. The size is probably more standardized than stuff you can get on ebay, though.


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