A Challenging Question on Bacteria . . .

[aqua_chem]

Someone made the comment that scientific experiments weren't necessary.. but IMO, to get a definitive answer on most of the questions brought up, they are. One can only speculate that most bacteria live in the filter in the majority of tanks. I can tell you that I've got two tanks running with no filter media. One is lightly stocked with only a bristlenose and 4 otos (29g). The other is a 150g that's pretty heavily stocked. Both are planted. Both only have mechanical filtration that's replaced (not rinsed) every week or two. I've yet to detect any ammonia or nitrite, and very very little nitrate in either tank. This leads me to the suggestion that bacteria will make themselves a home wherever necessary... I don't know all the science behind the various types of bacteria, whether they are free swimming or not, etc etc... I do know that what I've done has worked for me (for 4 months now... not a big acheivement, but promising.

FWIW, I did it as a test and it worked. I tried on a smaller scale first, and it worked.

I would credit your plants before I credited the bacteria. The low nitrate attests to that.

 

[Mumma.of.two]

I have a silly question I think I already know the answer to.

A lesson i learnt not long ago was very interesting and only thanks to a more knowledgeable fish keeper helped more sort it out! I dissmantled a six foot tank and placed some of the fish into a four foot set up with the filter,wood substrate decor etc,so my theory being the tank would be instantly cycled,so proceeded and all went well,but the tank took nearly six months to settle? The problem was that although the filter was mature as was the water,decor etc,because the tank was now smaller with a lighter bio load the bacteria had to readjust hence the tank remaining looking 'murky' until the bacteria had readjusted? Also Simon me mate up the local fish shop also agreed with me in that the bacteria levels in an aquarium are only as numerous as the amount of food {fish waste} available to them,so when we place new fish into the aquarium they have to multiply to compensate,which may only take a day or two,hence why we should never put to many fish into a tank and leave it at least a fortnight between getting new fish?

I it possible to get a mini cycle from the die off of BB in your tank due to the lack of food(down grading like above)? Do their little dead 'bodies' contribute to the ammonia? If during a power outage the BB in a filter (assuming mostly in the filter because the bacteria in the tank itself still has access) or anywhere else dose not receive enough water flow to keep up to it's needs?

 

[aqua_chem]

Eventually, yes, you can starve off a lot of your BB if they are denied a source of food. The population that develops in the filter is only possible with ample flow delivering a constant supply of food.


I don't think that bacteria have the biomass to cause an appreciable ammonia spike. If anything, the survivng bacteria would go donner party on the bacteria that die off.

 

[eco23]

I would credit your plants before I credited the bacteria. The low nitrate attests to that.

I was about to say the same. It stands to reason that if a well planted tank is consuming the toxins...there is no need for a large bio-filter to establish itself in the first place.

As for my not needing lab coats and microscopes comment. I stand by it. While great information comes from the scientific aspect of things...IMO, experience and knowing what works in a practical application is sufficient.

My personality may also different from some. While I enjoy the science of things and certain aspects interest me, there are simply things I don't need to know.

For example, I have what I call my "Dishwasher Ideology". I have a dishwasher which I put plates into, pour in soap in and turn it on. As long as the plates come out clean...I'm happy. Honestly I don't care what temperature the water heats up to, how the soap is dispersed throughout the machine, what mechanism they use to disperse water, etc...

If I know through personal experience as well as that of countless others that the majority of nitrifying bacteria is in the filter media...that's good enough for me. And I don't need a microscope or lab coat to tell me so.

 

[NoMoreGoldFish]

Really? Why? we're talking about about viable bacteria populations found on other surfaces than the filter media are we not? The water column and the substrate?

Look at it this way, bacteria need a food source to survive, and the majority of the feces and uneaten food are on your filtering pads and filter media. The bacteria that end up on your filter media will survive and multiply, the ones that are floating in your tank water will simply die out once all the ammonia and nitrite are depleted (when you use a test kit and do a test on NH3 and NO2 and the results read zero). That is why it's impractical to seed a new aquarium with water from an established tank, because the effect on the cycling time is negligible.

As to why the substrates of your tank have less nitrifying bacteria than your filter media when there's plenty of fish feces in them to feed the bacteria, think surface area and water flow. A filter media like Eheim's Ehfisynth has a surface area of about 18,000 square feet per gallon of media because of their porous nature, you can't compare any kind of substrate to it, not even very fine sand. Why then can people sometimes use sand in their filter system like the deep sand bed filter? That leads to my next point, water flow. The sand substrate people have on the bottom of their tanks have very little water flowing through them, so little that over time toxic gas pockets containing anaerobic bacteria will develop. That also means that the bacteria on your sand substrate will not get enough oxygen to survive even if there's enough food for them.

Beneficial bacteria do live on the surface area of your gravel, but there are a lot less of them because of the reasons above. Most of your bacteria will live on your filter media because they thrive in that environment. It's the same with we humans, coastal cities and cities that are near rivers and streams are almost always more densely populated because it's easier for us to get the resources we need to survive in those areas. So basically geographically speaking, your substrate is comparable to a desert, and your filter media to, I don't know, maybe Sydney in Australia.

 

[adeebm]

Look at it this way, bacteria need a food source to survive, and the majority of the feces and uneaten food are on your filtering pads and filter media. The bacteria that end up on your filter media will survive and multiply, the ones that are floating in your tank water will simply die out once all the ammonia and nitrite are depleted (when you use a test kit and do a test on NH3 and NO2 and the results read zero). That is why it's impractical to seed a new aquarium with water from an established tank, because the effect on the cycling time is negligible.

As to why the substrates of your tank have less nitrifying bacteria than your filter media when there's plenty of fish feces in them to feed the bacteria, think surface area and water flow. A filter media like Eheim's Ehfisynth has a surface area of about 18,000 square feet per gallon of media because of their porous nature, you can't compare any kind of substrate to it, not even very fine sand. Why then can people sometimes use sand in their filter system like the deep sand bed filter? That leads to my next point, water flow. The sand substrate people have on the bottom of their tanks have very little water flowing through them, so little that over time toxic gas pockets containing anaerobic bacteria will develop. That also means that the bacteria on your sand substrate will not get enough oxygen to survive even if there's enough food for them.

Beneficial bacteria do live on the surface area of your gravel, but there are a lot less of them because of the reasons above. Most of your bacteria will live on your filter media because they thrive in that environment. It's the same with we humans, coastal cities and cities that are near rivers and streams are almost always more densely populated because it's easier for us to get the resources we need to survive in those areas. So basically geographically speaking, your substrate is comparable to a desert, and your filter media to, I don't know, maybe Sydney in Australia.

Just want to point out that concentration of nitrifying bacteria has little to do with where feces and food collect. The bacteria don't eat the waste matter directly. Other bacteria consume the waste, and release ammonia as a byproduct. Fish themselves release ammonia directly, along with waste matter. The ammonia is aqueous, and spread out through the water. The reason there are more bacteria in the filter is due to flow like you said, not because waste matter collects there. A higher flow rate means more ammonium ions pass through, and can be processed.

--Adeeb

 

[aqua_chem]

As for my not needing lab coats and microscopes comment. I stand by it. While great information comes from the scientific aspect of things...IMO, experience and knowing what works in a practical application is sufficient.

My personality may also different from some. While I enjoy the science of things and certain aspects interest me, there are simply things I don't need to know.

For example, I have what I call my "Dishwasher Ideology". I have a dishwasher which I put plates into, pour in soap in and turn it on. As long as the plates come out clean...I'm happy. Honestly I don't care what temperature the water heats up to, how the soap is dispersed throughout the machine, what mechanism they use to disperse water, etc...

If I know through personal experience as well as that of countless others that the majority of nitrifying bacteria is in the filter media...that's good enough for me. And I don't need a microscope or lab coat to tell me so.

I don't mean this in a person way at all, but to me, that's just such a buzz kill. One of the reasons that I got into science was a love of the complex, confusing, and intricate workings behind mundane, boring everyday occurrences. I love knowing why, what, and how many. Science offers us absolute answers that anecdotes can not offer us.

 

[Wy Renegade]

First off, sorry for being late to the party, afraid I got tied up with other things this evening.

As I said, perhaps I'm losing sight of what this thread is really about. Are we debating the viability... or the proportion of BB in the filter media vs. elsewhere?

Well, I have to say that I believed the debate was on the proportion of the BB (I assume this means something bacteria ~ sorry not familiar with all the acronyms you all use) in the filter media vs. elsewhere. But perhaps I also digressed a bit from the stated topic?

I think every one of us knows that the nitrifiers are found on every oxygenated surface of the tank, no debate there. If we're talking about viability in the sense that filter media is more efficient in cycling a tank based proportionally on the sheer volume of bacteria in media vs. other areas or water...I'm honestly surprised it's still a question.

I love threads like this because when questions are asked, especially ones that defy common belief, it leads to more answers and new information. That said, I am surprised this is the topic of discussion.

I'm glad the previous poster had success with his method, but I think we can mostly agree that is not the norm. The facts that we do know definitely seem to support what is considered and repeated as common knowledge in the hobby.

-Nitrifying bacteria are primarily surface adherers...though we can agree there will be some % in the water column if for no other reason than becoming dislodged

-Knowing what we do about their needs for efficient colonization, it appears filter media is the most hospitable environment for them for numerous reasons.

-Example after example of people donating established media compared to donating gravel and other items. Every single day I'm messaging with members (many of whom have never posted) during cycling. I've seen the efficiency of filter media compared to water / other items both in my own tanks as well as countless members

-Tons of testament from members that changing substrate has minimal impact on the bio-filter, while we see new members all the time having mini-cycles from replacing filter cartridges and other types of media.

-When someone upgrades to a larger tank, they can simply move the existing fish and filter to the new tank, and besides the small potential (rarely seen IME on the site) for a mini-cycle due to the loss of bacteria on other areas...we don't hear negative consequences.

While I am at this point willing to concede most of your points, I have to say that I still have issues with the two I've highlighted in red. Availability of oxygen and flow has not been proven to my personal satisfaction at this point by the debate. It appears to me that some additional piece is still missing.

As for the second on the point of testimonials regarding cycles by disrupting substrate perhaps I've simply not read enough threads.

I believe there's not one of us on this thread who would advise another member just to move over all their fish, water and substrate and consider it cycled, or virtually cycled like it is by moving over the established filter.

Indeed and with most of today's set-ups I would have to say that I would agree with this statement as well.

 

[eco23]

I don't mean this in a person way at all, but to me, that's just such a buzz kill. One of the reasons that I got into science was a love of the complex, confusing, and intricate workings behind mundane, boring everyday occurrences. I love knowing why, what, and how many. Science offers us absolute answers that anecdotes can not offer us.

Fair enough. Like I said, different strokes for different folks. I was responding to Rookie's comment aimed towards my earlier post when I said that knowing the answer to something doesn't always require a full scientific breakdown, especially in situations like this where the legwork has already been put in and the information and science already exists and is readily available to anyone with Internet access or a library card (do those still exist?). IMO, this topic, while very interesting and thought provoking on some levels, fits into that category. No disrespect towards the science or people who have a passion for the details of it...I'm just simply saying you don't need to have a formula scribbled out on a chalk board to know whether something is true or not.

 

[Wy Renegade]

Yes, bacterial growth is limited by space. If you look at population growth models, what's termed as the carrying capacity, or maximum poluation would here be defined by the available surface area. If you compare gravel to ceramic(or other) biomedia, you will see a vast difference in surface area. Gravel is basically spherical, and has a surface area of 4pir^2. Biomedia on the other hand, is engineered to have an enormous surface area for its volume, which is the point of biomedia. Is there flow through gravel? Yes there is. It is however far less than the flow through a filter. That combined with the low surface area of gravel is why a filter is much more efficient at holding a population of bacteria. There is no denying that the gravel and all surfaces of the tank are colonized, but groth factors will dictate exactly what the population per volume is.

And yet I'm still forced to question this based on the accepted occurrence of these same nitrifying bacteria within both the LR and the LS of a saltwater aquarium. But, perhaps as was stated, these are different strains of bacterium and comparisons cannot be made. Perhaps a future topic of study for those with white lab coats and a microscope?

Flow is volume over time. If say a filter is rated for 160gph, 160 gallons of water pass through the filter media in an hour. This is significantly more than what passes through an equivalent volume of gravel or sand. This is especially tru in FW where the use of powerheads is often not employed.

Perhaps, and yet I'm not sure that I'm fully prepared to accept this. If the filter is moving 160gallons per hour across its media, it has to be generating a significant volume of flow within the tank as a whole, water within the aquarium does not (at least in most cases) move independently of the other water in the tank without some sort of barrier interfering with this flow. If it did, the proportion of the water in proximity to the filter would in fact be better filtered that the water further away. A testing evidence does not support this thought.

As for the dentrifying bacteria you are talking about, that is an entirely different beast. Dentrifying bacteria convernt nitrates into N2 gas, in order to utilize the oxygen bound in NO3. Denitrfying bacteria are anaerobic, and are found in conditions lacking oxygen. They are often relied upon in SW systems to maintain 0 nitrates, since in SW even small amounts of nitrates can be devastating to coral. These bacteria live deep within liverock, and at the bottom layer of a deep sandbed. As water flows through the LR or sand, it is stripped of oxygen by the nitrifying bacteria. By the time it reaches the deepest parts, there is little or no oxygen left. This is where the denitryfying bacteria live, and because of the lack of free oxygen, extract oxygen from NO3 molecules.

Indeed I concur, did I misstate somewhere?

Tanks without LR but with a DSB may be succesful, but will not be able to handle the same level of bioload is those with LR. These systems often rely on heavy use of protein skimmers to remove DOCs before they can decay. Even then, the lack of LR will limit stocking capacity.

I tend to think that there are a fair number of proponents of DSBs who would challenge that statement, but that is a topic for a different time.

You can run an FW system without an HOB if you wanted to. Get a 55 gallon with a powerhead or two and lots of gravel. Cycle it, then drop in a few guppies. The gravel will be able to handle it. However, your bioload capacity will be limited and if you want large schools of fish, you will need to increase your bacterial capacity with filters.

This is perhaps a topic for future debate, but I think it would in fact come down at least in part to the question of what defines a "filter". Aquariums with UGFs were and still are run successfully with large bioloads that rely only upon bacterial populations within gravel. Again however, that depends upon your definition of a filter, and takes the topic of discussion in an entirely different direction than I wish to go at this point.

With bacterial populations, it all comes down to available space and nutrients, as with any population. Space determines the maximum capacity, and the availability of nutrients(oxygen, ammonia, etc) will determine the exact population. That's all you need when comparing the efficiency of different medias/surfaces for bacterial growth capacity.

Indeed, space would in fact appear to be, at least in a large part the answer to the question, and yet I do believe that I did concede in my initial post that modern media has more surface area available. I believe that my initial question was more to the point of total volume of bacteria in the comparability small area of the filter vs. the total volume of bacteria in the much larger area of the substrate. Something to the fact that the majority of beneficial bacteria are found within the filter media.

The bacteria in gravel is, Im sure, an important factor in keeping ammonia levels down. But on a per volume basis, an HOB filter is far more efficient. If I have a filter with a volume of one gallon, or one gallon of gravel, which do you think would be able to process more ammonia?

--Adeeb

Indeed I concede this point without debate (as I believe I did in my initial post), there is no question that modern filter media has a much greater ability to hold bacteria than gravel or even sand.

 

[Wy Renegade]

We should get a batsign or something of the sort for when these conversations begin so that I can get to the party on time!

LOL, don't you get one of those email messages telling you when a new post has be made in the thread ? I kid, I kid. Sometimes other things keep us away from the party.

Ok, napkin math!

Let's model a gravel substrate of negligible porousity (which i think is pretty reasonable for many aquarium gravels) as being composed exclusively of perfect spheres packed together in closest packed manner. Packed like this, about 75% of the volume is occupied by spheres. Thus, if we divide by the volume of a sphere (4/3 π r^3) we get the total number of spheres, and if we multiple by the surface area of a sphere (4π r^2) we get:

SA = 2.25 * A*(d/r)

Where A is the area (footprint) of your tank, d is the depth of the substrate, and r is the radius of your spheres. For these calculations, I'm only using a depth of 1" for substrate, as anything more than that doesn't have appreciable bacteria levels. Assuming a 3mm diameter of aquarium gravel (a popular size), and using generous footprint (40breeder), I get the total available surface area to be....

About 171.5 square feet. Compared to the 15000 square feet from Ehfisubstrat (which is actually closer to 1/3 an acre), that's about 1%.

Ah, thank you ~ this in fact is much more to point of what I was after. Now arguable the % would be higher for sand vs. gravel, but still would appear to fall far short of the modern media. That would indeed appear to be the crux of the methodology that proves my hypothesis incorrect.

If anything is using the nitrogen in the water column, I think that it would be these guys. I really think that the various fauna in the water column might have a surprisingly profound impact on our aquariums' ecologies.

Indeed, and perhaps again a very interesting topic for further debate.

I'm pretty positive on this one. Nitrifying bacteria get energy by oxidizing reduced forms of nitrogen. I believe the technical term for them is chemolithotropes. They are technically autotropes (specifically chemoautotropes), but definitely chemotropes. They are definitely not phototropes, which most people associate with autotrophy.

Indeed you were in fact correct, and I was incorrect on this point. I apologize.

In terms of sheet numbers though, there are probably millions of more bacteria on surfaces than in the water column. Keeping in mind that bacteria multiply by doubling, that us a HUGE head start over simple water column seeding. Bacterial proliferation occurs on a log scale whereas purification occurs linearly. So if I transfer 1000 bugs over in the water column to one tank and a million over to another one by seeding of some other sort, then the later tank will always have a million fold more bacteria than the other, assuming that they multiple at the same rate, and only until the later hits the limit of supportable bacteria.

Agreed, but again I would point out that I never advocated for simple water transfer. Rather the transfer of vacuumed water from the substrate which is a beast of a totally different color.

 

[Wy Renegade]

Someone made the comment that scientific experiments weren't necessary.. but IMO, to get a definitive answer on most of the questions brought up, they are. One can only speculate that most bacteria live in the filter in the majority of tanks. I can tell you that I've got two tanks running with no filter media. One is lightly stocked with only a bristlenose and 4 otos (29g). The other is a 150g that's pretty heavily stocked. Both are planted. Both only have mechanical filtration that's replaced (not rinsed) every week or two. I've yet to detect any ammonia or nitrite, and very very little nitrate in either tank. This leads me to the suggestion that bacteria will make themselves a home wherever necessary... I don't know all the science behind the various types of bacteria, whether they are free swimming or not, etc etc... I do know that what I've done has worked for me (for 4 months now... not a big acheivement, but promising.

FWIW, I did it as a test and it worked. I tried on a smaller scale first, and it worked.

Indeed, and perhaps this gets far more to the crux of my own questions in regard to this issue, as I do not run a single aquarium that would meet with eco's or the majority of this forums members definition of a normal aquarium or normal filtration. Perhaps part of why I raised the question. Perhaps I am totally mistaken in believing that the flow equates throughout the aquarium.

Like yourself however, I have to state that I also believe that definitive answers will only be generated by those in white lab coats with microscopes. Antecedent evidence certainly has its place, but leads only to postulation, never to definitive answers.

I also don't think that space is a huge issue actually. Most bacteria can attach to other bacteria and form colonies. So when they don't have enough room to grow out anymore, they would probably simply grow up. I would think that they would hit a nutritional barrier long before they hit a spacial one.

Hhhhmmm, yet another interesting thought. I shall have to mull this one a bit more perhaps.

 

[Wy Renegade]

I would credit your plants before I credited the bacteria. The low nitrate attests to that.

I was about to say the same. It stands to reason that if a well planted tank is consuming the toxins...there is no need for a large bio-filter to establish itself in the first place.

Not necessarily. I really would like to see a comprehensive list of aquatic plants which are capable of absorbing and using ammonia ~ such a list might go a long ways toward answering some of these questions.

Eventually, yes, you can starve off a lot of your BB if they are denied a source of food. The population that develops in the filter is only possible with ample flow delivering a constant supply of food.


I don't think that bacteria have the biomass to cause an appreciable ammonia spike. If anything, the survivng bacteria would go donner party on the bacteria that die off.

Based on the evidence of algal blooms that might be topic for some further discussion.

As for my not needing lab coats and microscopes comment. I stand by it. While great information comes from the scientific aspect of things...IMO, experience and knowing what works in a practical application is sufficient.

If I know through personal experience as well as that of countless others that the majority of nitrifying bacteria is in the filter media...that's good enough for me. And I don't need a microscope or lab coat to tell me so.

Again, I would point at as stated earlier that in truth you don't know, you postulate and that indeed is a significant difference. You cannot for fact state empirically with any degree of accuracy that HOB filters truly contain more bacteria than a much larger volume of substrate, because you have no definitive or empirical evidence to support your position. You have only antecedent evidence that could in fact be proven completely incorrect at any point and time by scientific evidence.

 

[Wy Renegade]

Look at it this way, bacteria need a food source to survive, and the majority of the feces and uneaten food are on your filtering pads and filter media. The bacteria that end up on your filter media will survive and multiply, the ones that are floating in your tank water will simply die out once all the ammonia and nitrite are depleted (when you use a test kit and do a test on NH3 and NO2 and the results read zero). That is why it's impractical to seed a new aquarium with water from an established tank, because the effect on the cycling time is negligible.

As to why the substrates of your tank have less nitrifying bacteria than your filter media when there's plenty of fish feces in them to feed the bacteria, think surface area and water flow. A filter media like Eheim's Ehfisynth has a surface area of about 18,000 square feet per gallon of media because of their porous nature, you can't compare any kind of substrate to it, not even very fine sand. Why then can people sometimes use sand in their filter system like the deep sand bed filter? That leads to my next point, water flow. The sand substrate people have on the bottom of their tanks have very little water flowing through them, so little that over time toxic gas pockets containing anaerobic bacteria will develop. That also means that the bacteria on your sand substrate will not get enough oxygen to survive even if there's enough food for them.

Beneficial bacteria do live on the surface area of your gravel, but there are a lot less of them because of the reasons above. Most of your bacteria will live on your filter media because they thrive in that environment. It's the same with we humans, coastal cities and cities that are near rivers and streams are almost always more densely populated because it's easier for us to get the resources we need to survive in those areas. So basically geographically speaking, your substrate is comparable to a desert, and your filter media to, I don't know, maybe Sydney in Australia.

While I understand your point, and agree that it certainly applies to the deeper portions of the substrate, I'm still not convinced that it holds true with the upper portions of the substrate.

 

[Wy Renegade]

Fair enough. Like I said, different strokes for different folks. I was responding to Rookie's comment aimed towards my earlier post when I said that knowing the answer to something doesn't always require a full scientific breakdown, especially in situations like this where the legwork has already been put in and the information and science already exists and is readily available to anyone with Internet access or a library card (do those still exist?). IMO, this topic, while very interesting and thought provoking on some levels, fits into that category. No disrespect towards the science or people who have a passion for the details of it...I'm just simply saying you don't need to have a formula scribbled out on a chalk board to know whether something is true or not.

I think that if we were to search through the pages of history, we could in fact find many instances were this very attitude has been proven wrong many times over. In fact, I would point out that it was this very attitude that lead human society into that extremely trying time period known as the dark ages.

The simple fact that you are forced to accept the fact that mine and others experiences are also accurate, although very different from your own and perhaps what you and the majority of others on this forum consider to be the norm shows that you in fact do not have all the evidence, and there are cases that do not fit your definition or experiences of how things work. This alone proves that there are further questions to be answered regarding this particular topic and only by challenging the accepted norm in this manner do we move towards answering those questions. If in fact we are simply content to sit and accept what currently works as the best and final answer we stagnate. If your stated position were in fact true, we would have been content long ago that UGF were the definitive answer to filtration and we would not have progressed forward from that point.

You yourself are evidence to the case in point. You once argued with me over the very definition you now use for "cycled". You have undertaken significant research into the question of cycling and by doing so you have increased your knowledge base. You also stated that you have conducted experiments of your own on this topic.

Despite assumptions to the contrary, all available answers are not yet to be found on the internet or in the library.

 

[aqua_chem]

Ah, thank you ~ this in fact is much more to point of what I was after. Now arguable the % would be higher for sand vs. gravel, but still would appear to fall far short of the modern media. That would indeed appear to be the crux of the methodology that proves my hypothesis incorrect.

Ran the numbers again for medium grit, .4 mm diameter sand. You end up with 10x the surface area, around 1500 square feet. Still about 10% of the ceramic substrate though. Also, at a depth of one inch, sand will be getting significantly less nutrient flow, leading to the idea that there would be less nitrifying at that depth.

 

[Wy Renegade]

To all participating members, I appreciate the debate/discussion. I appreciate that the debate and discussion was conducted in a mature and respectful manner, and I continue to look forward to more meaningful discussions on this topic as well as others. We are all here to learn, not a single one of us has at this point learned everything there is to know about aquarium keeping, and I appreciate your willingness to allow me and others that opportunity.

Cheers!

 

[adeebm]

To all participating members, I appreciate the debate/discussion. I appreciate that the debate and discussion was conducted in a mature and respectful manner, and I continue to look forward to more meaningful discussions on this topic as well as others. We are all here to learn, not a single one of us has at this point learned everything there is to know about aquarium keeping, and I appreciate your willingness to allow me and others that opportunity.

Cheers!

These threads we've been making recently really get ya to think don't they? Hopefully we'll have a lot more and we can further advance our knowledge of fishkeeping!

P.S. I kinda want to try an FW tank with LR and a DSB now. That would be quite fun...

--Adeeb

 

[Wy Renegade]

Ran the numbers again for medium grit, .4 mm diameter sand. You end up with 10x the surface area, around 1500 square feet. Still about 10% of the ceramic substrate though. Also, at a depth of one inch, sand will be getting significantly less nutrient flow, leading to the idea that there would be less nitrifying at that depth.

Indeed, so the math, as anticipated supports the statement that significantly more surface area is found within the surface area, and even by applying the greater volume we still end with significantly more less surface area. Empirically then the surface area questions have indeed been answered.

I do agree that at depths below an inch and perhaps even less than that, we will finding decreasing amounts of nitrification.

Still, I think that an experiment comparing actual bacterial growth of the desirable types would be of further interest. Such an experiment is unfortunately beyond my abilities however, as identifying the desirable strains vs. others would be very difficult.

Experiences outside the norm that obviously do occur continue to point to the fact that there is still more to be learned on this particular topic.

 

[Wy Renegade]

These threads we've been making recently really get ya to think don't they? Hopefully we'll have a lot more and we can further advance our knowledge of fishkeeping!

P.S. I kinda want to try an FW tank with LR and a DSB now. That would be quite fun...

--Adeeb

Indeed they do. I look forward to many more of the same as well.

Now that would be an interesting experiment wouldn't it. It also might give us some antecedent answers regarding the differences or non differences between fresh and saltwater nitrifying bacteria.