Poll: Where Does The Majority Of The Beneficial Bacteria Reside?

HI guys! I am starting a poll here to get opinions on this matter. And I would LOVE it if anyone has actual PROOF to back up their answer!! Because I am getting a lot of long timers trying to tell me that the majority of our BB resides in our substrate. And telling new people that they can just replace their entire filter without any concerns because the majority of the BB is in the substrate.

Now...I know that BB resides on ALL surfaces. Substrate, ornaments, walls etc. But from what I have always understood...the MAJORITY is in the filter itself. Where the water is constantly flowing through!

I am someone who entered the hobby within the last 10 years. So I have done a lot more research than most long timers thanks to the internet. And that isn't to say long timers are irresponsible! When they started the hobby, the internet didn't exist!! So everything they learned, they learned through experience and word of mouth. And if it has always worked for them, then it must be the right way to do things. If I had been doing something one way for decades....and it worked just fine for me....then I would see no reason to behave like a beginner and actually go online and research everything I have done to make sure it was correct! Nor would I believe a newer hobbyist would know better than myself when it comes to a topic like this if I had been doing it for 30 years!! (hey I can admit it! haha)

The other thing the long timers keep saying is that you can cycle a new tank by doing nothing more than squeezing a dirty filter sponge into the water of the new tank. That one baffles me as well! From what I understand, the majority of the bb on the sponge stays attached to the sponge!! If it didn't, we would lose it all when scrubbing the sponges in a bucket of tank water! Am I right?? So most of what you are squeezing into the new water is just poop, uneaten food and debris!! Not BB!

So here's the thing...I learned most of what I learned right here on fishlore. So I expect the majority here on fishlore to agree with me on this one (that the majority of our BB is in the filter) But I would love it if someone has a way they can PROVE to me, that there is just as much, if not more BB in the substrate itself!

Since the long timers have been keeping fish for decades and I have not...I feel they have a right to be overly confident in their opinions. And since I have no concrete physical proof that the filter has the majority of our BB and that squeezing dirty water into a tank will not cycle it...I have no leg to stand on in these debates!!

I would never in a million years tell someone that they can completely replace their entire filter and throw away all its media because their substrate will keep them cycled. I feel like that is setting the person up for disaster! So I am trying to save these people the heartache...but again, who is going to listen to me when folks doing it for decades are saying otherwise?

Please vote, but ALSO, please tell me why you voted the way you did. I am totally open to being proven wrong!!! I just want proof! One way or another!!!

Is this only a matter of opinion?? or can it be scientifically proven somehow??

Thanks guys!! I appreciate your input!

 

Hello Liz. Hope all is well. I have always understood it to be in lots of things but mainly in the filter.

 

They are where ever they can be that's not disturbed much. So in people who gravel vac constantly and clean their glass and decorations constantly, the BB will probably be in their filter. But if someone who lets their tank do it's own thing, the BB will be everywhere.

And I don't believe that BB will be in the filter more just because of flow. Flow is for debris, not chemicals / atoms. The chemicals would diffuse in the water evenly. If you test the water near the intake and water the furthest away, the readings would be the same.

The only thing flow does it gets BB established on the filter quicker because all the water leads that way. But BB can get slowly established everywhere, any they will compete with each other. Being near the filter doesn't give any benefit to out compete the BB elsewhere.

 

Nitrifying bacteria need a water flow so it will be mostly in the filter media, on the glass and the surface of your substrate. Denitrifying bacteria require low flow and little oxygen so that's what will be found deeper in the substrate.

 

It’s in the filter. Oxygen people!! They need oxygenated water!! What better place than the filter? The deeper you go into substrate, the less oxygen is available. My proof is that I’ve changed my entire substrate at once numerous times and have never had a minI cycle. I’ve tried to use “established” gravel when starting a new tank, it never worked like using established media. If they truly were in the gravel as is, people wouldn’t have invented undergravel filters (flow and oxygen again) and sponge filters with the sole purpose of harboring BB. If the majority were in the substrate then how would people be able to bare bottom? It’s not that they need water flow so much, it’s the oxygen that’s high in flowing water.

 

Nitrifying bacteria need a water flow so it will be mostly in the filter media, on the glass and the surface of your substrate. Denitrifying bacteria require low flow and little oxygen so that's what will be found deeper in the substrate.

Thank you! So what is the difference between the two types of bacteria? And would a tank remain cycled if most of the nitrifying bacteria is removed and you are left with only the denitrifying bacteria from the substrate?

 

I agree. I think it resides in the filter, mainly. My reasoning is that all of the debris and fish stool gets trapped in the filter. As that matter decays directly on the media, the BB is directly fed ammonia. It's like a feeding ground! Along with increased oxygen flow, I think it's the filter.

 

Thank you! So what is the difference between the two types of bacteria? And would a tank remain cycled if most of the nitrifying bacteria is removed and you are left with only the denitrifying bacteria from the substrate?

Your nitrifying bacteria are the ones that break down ammonia and nitrite. Denitrifying bacteria convert nitrate into nitrogen gas. And I should edit my first response. Flow is needed for oxygen and for the delivery of ammonia and nitrite.

 

No opinion, but following with interest...

 

Your nitrifying bacteria are the ones that break down ammonia and nitrite. Denitrifying bacteria convert nitrate into nitrogen gas. And I should edit my first response. Flow is needed for oxygen and for the delivery of ammonia and nitrite.

So doesn't that mean you will lose your cycle if you throw away the filter media then?

 

HI guys! I am starting a poll here to get opinions on this matter. And I would LOVE it if anyone has actual PROOF to back up their answer!! Because I am getting a lot of long timers trying to tell me that the majority of our BB resides in our substrate. And telling new people that they can just replace their entire filter without any concerns because the majority of the BB is in the substrate.

Now...I know that BB resides on ALL surfaces. Substrate, ornaments, walls etc. But from what I have always understood...the MAJORITY is in the filter itself. Where the water is constantly flowing through!

I consider myself an old-timer Never would I tell someone to throw away and replace all the media in their filters. I believe, but sadly have no actual proof, that the bacteria lives on everything in the tank. I do believe, but then still can't actually prove, that the strongest colony of bacteria lives on items closest to flowing water thus the filter and the area just below the output of said filter.

The bacteria there is getting the majority of the food it needs to grow. As always this is just my opinion gleaned from years of being in this hobby so can't really be proven.

I am someone who entered the hobby within the last 10 years. So I have done a lot more research than most long timers thanks to the internet. And that isn't to say long timers are irresponsible! When they started the hobby, the internet didn't exist!! So everything they learned, they learned through experience and word of mouth. And if it has always worked for them, then it must be the right way to do things. If I had been doing something one way for decades....and it worked just fine for me....then I would see no reason to behave like a beginner and actually go online and research everything I have done to make sure it was correct! Nor would I believe a newer hobbyist would know better than myself when it comes to a topic like this if I had been doing it for 30 years!! (hey I can admit it! haha)

Raising my hand here. There was no internet back when I got into this hobby. I had a little leaflet that gave me the basics. I learned a lot through trial and error. The main thing it stressed was keep the water fresh and clean. That is the one thing I still stress today.

Although I have been in this hobby for a very long time I will readily admit that I have learned a lot since I joined this forum. Even we old timers need a refresher course from time to time but we need to keep an open mind. I will admit though, I haven't really changed the way I do things but just because it works for me doesn't necessarily mean it will work for everyone.

The other thing the long timers keep saying is that you can cycle a new tank by doing nothing more than squeezing a dirty filter sponge into the water of the new tank. That one baffles me as well! From what I understand, the majority of the bb on the sponge stays attached to the sponge!! If it didn't, we would lose it all when scrubbing the sponges in a bucket of tank water! Am I right?? So most of what you are squeezing into the new water is just poop, uneaten food and debris!! Not BB!

I have to agree with you here. I can't imagine that muck helping to cycle a tank. In my opinion it is nothing more than the waste left after the bacteria has finished eating all the good stuff out of it. Again, I can't prove that but I would never advise using it to cycle a tank.

So here's the thing...I learned most of what I learned right here on fishlore. So I expect the majority here on fishlore to agree with me on this one (that the majority of our BB is in the filter) But I would love it if someone has a way they can PROVE to me, that there is just as much, if not more BB in the substrate itself!

Since the long timers have been keeping fish for decades and I have not...I feel they have a right to be overly confident in their opinions. And since I have no concrete physical proof that the filter has the majority of our BB and that squeezing dirty water into a tank will not cycle it...I have no leg to stand on in these debates!!

I would never in a million years tell someone that they can completely replace their entire filter and throw away all its media because their substrate will keep them cycled. I feel like that is setting the person up for disaster! So I am trying to save these people the heartache...but again, who is going to listen to me when folks doing it for decades are saying otherwise?

Please vote, but ALSO, please tell me why you voted the way you did. I am totally open to being proven wrong!!! I just want proof! One way or another!!!

Is this only a matter of opinion?? or can it be scientifically proven somehow??

Thanks guys!! I appreciate your input!

I didn't vote. If both was an option that is the one I would have chosen. Sadly I think this is one of the many things that can't be proven without some experimentation. One would have to have several tanks set up to run the tests.

 

Common sense tells me that they are mostly in the filter because, since they inhabit all surfaces in the tank, your filter should theoretically contain more surface area on the sponge and biomedia than the rest of the tank combined.
Take my favorite PhD, Dr. Stephen Tanner, who imports my beloved Poret foam for us...it has 440 SF of surface area per cubic foot of 30 PPI media. So my 3"x18"x20" 30PPI Hamburg Mattenfilter has roughly 275 square feet of surface area. I think I did the math right, someone check me I suck at formulas...440 SF per Cu. Ft. and I come up with .625 cu. ft. of filter foam. Not sure if I divide or multiply with the decimal there...
At any rate, that's a lot of bacteria condos...far more than the 51 SF of glass and the 1/2" pebbles.
Now, if someone has a Tetra pre-packaged filter cartridge in their Tetra stock ten-gallon filter and nothing else, then I'd say they may very well have more in the substrate if it's an inch or two deep and of a smallish grain size.
So I didn't pick an answer in the poll because, like a lot of things in this hobby...it depends.

Edit - Source: http://www.swisstropicals.com/library/swisstropicals-poret-foam/

 

Hard to give scientific proof as you can't really count BB and no one is going to do an exhaustive study with controlled data points.

BB takes time to colonize and establish itself in a tank. It will colonize faster in places where it encounters food (ammonia, nitrites and eventually nitrates). That happens to be in the filter. It will also colonize in the path of the water. After a few months, you can take the filter off and just run an air stone for some water movement and while you might get a mini-cycle depending on the stock, it will eventually stabilize (within days usually).

The brown stuff from a sponge isn't old food and poop. It's broken down to mulm and BB grows on that as well. I've started new tanks by squeezing a sponge or two into the tank. It usually takes 1-4 days to cycle but it's MUCH quicker than starting new or using BB in a bottle (which is almost the same principle).

I've also started new tanks with a cup of established gravel. I try to scoop up the mulm too. It also takes 1-4 days to fully cycle.

Now, some of this won't work if the tank is constantly being cleaned and scrubbed. This example will have most BB in the filter.

Nitrifying bacteria converts ammonia and nitrites to nitrates. Normally, you change water to lower nitrates but in nature, denitrifying bacteria will convert nitrates to nitrogen, completing the nitrogen cycle. Growing denitrifying bacteria can take 6+ months and are more fragile (die off faster) than nitrifying bacteria.

I have been moving away from using biomedia in most of my tanks. I still have them in my canisters that are on my display tanks (4) but my breeding and growout tanks (10) only have sponges as bio media, either in a HOB or in-tank sponge filter.

 

Skip to 35 minutes in this video. This video was used as proof by one of the folks encouraging people to throw away their filter and trust the substrate. Please give me your thoughts on this!!

 

Skip to 35 minutes in this video. This video was used as proof by one of the folks encouraging people to throw away their filter and trust the substrate. Please give me your thoughts on this!!

The reason why that works is because the BB colony grows to support the load. If you have a 1000gph filter filled with biomedia, it's eating all the food (ammonia/nitrites) so the BB colony in the gravel will be minimal.

It's all these nuances that create a balance in a tank so there's no 1 right answer.

I've been watching LRB's channel for a while and like most of his methods. He also turned me onto TetraColor Tropical Granules and my fish seem to do great on it. I actually have spawning from a lot of my groups that you wouldn't think would spawn in their current conditions like my tetras in hard water.

 

I guess there a few to look at this. Undergravel filters pull water threw the substrate providing it with flow and oxygen. We used those type of filters forever. I have a tank that has a cycle with nothing more then a short bubble bar under 2 inches of pea gravel. So you can have a cycle in substrate along. But it could be said that now your substrate is your filter so you can use the term filter pretty broad. If you throw out your filter media you will lose what bacteria is in it. Now you nitrifying bacteria self replicate in between 7-14 hours depending on temp. So how mature your tank is and how high your bio load is would determine if you would lose your cycle.

 

The answer here is the undergravel filter. They were big years ago. The filter was under the gravel and it pulled water through the gravel into the filter. Thus that’s where the bb lived. Water running through the gravel and bb growing on the gravel and eating the waste. So back than before hobs and canisters. That’s where the bb grew. Now nobody uses undergravel filters so your bb is growing in the hob or other type of filter. Yes there s bb on everything but the majority is where the water is flowing thru.

 

These undergravel filters were also the reason for old tank syndrome. All the muck would sit under the filter at the bottom of the tank. After time it was uncleanable. High ammonia and nitrates. So you would have to take everything out clean under the filter and start again. Usually once a year.

 

People keep mentioning oxygen, but there's a cap on oxygen. Mainly a man living in the middle of a city gets more than enough oxygen as a man living in a rainforest next to the ocean. If your fish ain't gasping at the filter or top of the tank, there's plenty of oxygen all over the tank.

Again, I see no advantage of bb being on the filter.

 

My brain hurts! haha

Let me just break down what is going on in my head right now.

First...the oxygen/flow factor. I guess you could say that even if substrate alone is able to hold enough BB to keep a tank cycled.....it would never have more BB than the filter itself simply because the BB naturally flocks to the oxygenated areas. Am I understanding that correctly? So if you are running a filter on the tank (one that actually has sufficient biomedia in it of course) the majority of the BB will be in the filter for that reason. But if you have no filter running, or a filter with insufficient media, then the substrate may be carrying the majority?

I didn't officially vote myself, but with that being said, I think I will officially vote that the majority of the BB is in the filter IF it has a sufficient amount of biomedia. Simply due to the oxygen/flow factor.

This brings me to the undergravel filters. Using an undergravel filter will obviously change the above conclusion. But as david1978 said....by doing that, then the substrate is a filter. Not just substrate. Hence the name "undergravel filter". lol So then the vote still goes to "the filter".

That video above, 35 minutes in, is what gets me though!!! It goes against everything I thought I knew! There is no under gravel filter, no sponge filter, no HOB filter, no canister filter. No biological filtration at all. I feel like for that to actually work, your tank has to be very well established, and not get much glass or substrate cleaning. I mean honestly, how does that work? I genuinely don't get it. Are you able to do regular substrate cleanings? or do you have to just leave it be? Can you regularly clean your glass? Like....does going without a filter mean you sacrifice cleanliness? I am genuinely trying to understand this. I am not discounting anyone's opinions.

 

Then you have to consider gravel vs sand. Flow will penetrate farther into larger gravel since it has more voids. If you used lava chunks and some kind of flow pump you would filter a freshwater tank just like live rock does in saltwater.

 

These undergravel filters were also the reason for old tank syndrome. All the muck would sit under the filter at the bottom of the tank. After time it was uncleanable. High ammonia and nitrates. So you would have to take everything out clean under the filter and start again. Usually once a year.

Back in the late 80's, I ran a UGF on a 55 gallon with oscars (3) and a 30 gallon community. I alternated half gravel vacs every month. I was using pea gravel so I got most of the mulm out. I remember moving the gravel to clean under the UGF and it wasn't that dirty.

I remember I had air stones to run it but all the cool kids had a power head on the uplift tubes. Being a broke HS student, I couldn't afford them so I stuck being the nerd with air stones.

My brain hurts! haha

Let me just break down what is going on in my head right now.

First...the oxygen/flow factor. I guess you could say that even if substrate alone is able to hold enough BB to keep a tank cycled.....it would never have more BB than the filter itself simply because the BB naturally flocks to the oxygenated areas. Am I understanding that correctly? So if you are running a filter on the tank (one that actually has sufficient biomedia in it of course) the majority of the BB will be in the filter for that reason. But if you have no filter running, or a filter with insufficient media, then the substrate may be carrying the majority?

I didn't officially vote myself, but with that being said, I think I will officially vote that the majority of the BB is in the filter IF it has a sufficient amount of biomedia. Simply due to the oxygen/flow factor.

This brings me to the undergravel filters. Using an undergravel filter will obviously change the above conclusion. But as david1978 said....by doing that, then the substrate is a filter. Not just substrate. Hence the name "undergravel filter". lol So then the vote still goes to "the filter".

That video above, 35 minutes in, is what gets me though!!! It goes against everything I thought I knew! There is no under gravel filter, no sponge filter, no HOB filter, no canister filter. No biological filtration at all. I feel like for that to actually work, your tank has to be very well established, and not get much glass or substrate cleaning. I mean honestly, how does that work? I genuinely don't get it. Are you able to do regular substrate cleanings? or do you have to just leave it be? Can you regularly clean your glass? Like....does going without a filter mean you sacrifice cleanliness? I am genuinely trying to understand this. I am not discounting anyone's opinions.

Think of BB as algae, not a moving band of gypsies (they don't "flock" anywhere) . They grow on all surfaces where the food is (ammonia, nitrites, not oxygen). It will grow denser if there's an abundance of food.

Biomedia is good but there is a point of diminishing returns. More isn't always better and most of the time it can be just a waste of money.

In the video, LRB has a well established and balanced tank so there is minimal maintenance to keep it looking good. Most of the fish waste gets broken down and absorbed into the substrate where the plants use it up. He has a video where he pulled all the crypt to sell off and when he pulled it out of the gravel, all the mulm came out and you can see the buildup. It's not bad for a tank, it just doesn't look great. Cleaning the glass is fine as there's minimal BB because of the flat surface area.

This is interesting because when I got back into the hobby a couple of years ago, most of what I knew was still in practice but now it was all scientific-y. There was (is) also a lot of misinformation that people just parrot w/o knowing the actual reason behind the methods. Very little is set in stone so there are many ways to accomplish things in this hobby.

 

The reason why that works is because the BB colony grows to support the load. If you have a 1000gph filter filled with biomedia, it's eating all the food (ammonia/nitrites) so the BB colony in the gravel will be minimal.


It's all these nuances that create a balance in a tank so there's no 1 right answer.

I've been watching LRB's channel for a while and like most of his methods. He also turned me onto TetraColor Tropical Granules and my fish seem to do great on it. I actually have spawning from a lot of my groups that you wouldn't think would spawn in their current conditions like my tetras in hard water.

My Fish go crazy for TetraMin tropical flakes. They seem to grow quicker on it too. That and Hikari. Never again will I fall for marketing tricks from brands like NLS and Omega One.

 

. Never again will I fall for marketing tricks from brands like NLS and Omega One.

Am I a sucker? Maybe I should stop with omega one too. Lol

 

Am I a sucker? Maybe I should stop with omega one too. Lol

If you are I am too. I feed mostly Tetramin Tropical Crisps and flakes but I also rotate several different Omega One and HikarI products too.

 

Getting way off topic but I was watching LRB's videos and just about every one mentions TCTG so out of curiosity, I looked into it and liked the ingredients and nutritional values so I tried a can. I liked it so much I bought another. Then it went on sale and I bought 2 more. I bought a coffee bean burr grinder just to grind it down to almost dust for my fry/juveniles. Every single fish, pleco, shrimp have jumped on it from the start.

The 10.5oz can is at the sale price of $6.80 shipped (prime) on Amazon.


I still have a ton of frozen and dried foods but TCTG is the main staple for most of my fish. It might be the secret sauce for most of my fish spawning all the time.

 

Well I stopped feeding Omega one after I got stabbed with a fish bone. Lol

 

Realistically, I don't think there is a single answer to this question which will be correct in every case. Does the flow of water through filter media allow for a higher concentration of bacteria on the surface area of the media? If so, is it due to increased oxygen levels, increased availability of dissolved nutrients, or...?

My tanks use large...and I mean large...sponge filters. The matten filter in the 360-gallon tank I had in my last home was 3 feet x 2 feet x 5 inches thick. I had very little substrate in there, grew plants in pots, used floaters and others like Java Fern that grow on pieces of wood. I am pretty certain that the surface area of the foam block exceeded the surface area of the interior of the tank and all its furnishings, but can't say for sure. If I'm correct, then it stands to reason that the foam block contained more bacteria than the rest of the tank. Swiss Tropicals, who import the Poret foam I use now, can probably provide a figure for the surface area of their foam, but I haven't checked.

On the other hand, if you have a tank filtered by a canister filter with a limited volume of biological media, and especially if you have a deep substrate, it seems reasonable to assume that the filter will contain less bacteria than the rest of the tank.

I remember the old saw about squeezing a dirty old filter out into a new tank. It was just a way of introducing a good starter culture of beneficial bacteria without actually robbing the older "donor" tank of its mature filter. The gunk coming out of the filter is solid waste, rather than dissolved material...and since it is solid, the tiny particles that make up that yummy-looking brown cloud will each be covered with bacteria. You're basically transferring part of the bacterial culture by dumping in that gunk. I wouldn't hesitate to do that, but I prefer just having an extra sponge filter set up and matured in another tank, and then plopping that into the new tank. Presto! Instant cycle, no cloud of poop.

I also used a lot of undergravel filters back when they were considered high-tech, although most of mine were homemade. I always tried to arrange a method to drain water from underneath the plates, which allowed the removal of that fine particulate matter than accumulated there. More efficient methods included the use of reverse-flow undergravel filters, which pumped filtered water down under the gravel and thus forced the direction of flow to be upwards, while at the same time removing the bulk of the particulate matter and extending the periods between flushing out the undergravel plenum. None of these methods were perfect, but somehow fish lived, plants grew and aquarists enjoyed their tanks.

"Old-tank syndrome" is, IMHO, a crock. If you use an effective filtration method AND practice regular large-scale water changes, you will NEVER experience old-tank syndrome. Newer filters are probably somewhat more efficient and, more importantly, easier to service and clean than in the bad old days...but it's the changing of water that is the easiest and most fool-proof way to avoid the "syndrome". The no-water-change aquariums that every second thread on Fishlore focusses on can probably be made to work...IF they are set up and maintained by someone who truly understands all the nuances of the nitrogen cycle and water chemistry in general. But, if you read some of those threads, you quickly see that is almost never the case.