Beneficial Bacteria accommodation

[Mr Gumby]

Just curious if anyone has come across any studies on what percentage of bacteria actually live in your filter?

I've had multiple shall we say discussions with people who insist they pretty much all live in your filter. 

Now I dare say that in big open aquariums with minimal decor that is more than likely the case but in our planted tanks with a bunch of wood, rock and substrate I highly doubt it.

I'd love to be able to reference an actual study if one exists rather than my own fish room science

[lefty o]

anything in the tank with a surface for them to be on, is where they are. about the only thin in an aquarium that has little to no beneficial bacteria is the water itself.

[Mr Gumby]

On 1/10/2022 at 3:27 PM, lefty o said:

anything in the tank with a surface for them to be on, is where they are. about the only thin in an aquarium that has little to no beneficial bacteria is the water itself.

Yep, that's my take on it but I'd love to be able to link that to some science

[HH Morant]

Aquariumscience.org has some articles about the subject of beneficial bacteria. I am not sure exactly which article contains this information, but as I recall the author says that, even in a poorly filtered aquarium, 90% of beneficial bacteria is in the filter. This is because the beneficial bacteria need surface area and flow, and generally there is not enough flow in the aquarium to support large numbers of beneficial bacteria. I am not sure if the author cites any studies.

Under-gravel filters and powerheads aimed at the substrate would be exceptions to this rule because they create flow in the substrate.

The flow in the filter is what allows large numbers of beneficial bacteria to live there.

In 2020 I had an experience which makes me think this is correct. I bought a used aquarium with a used substrate, which I kept wet during the move of the aquarium. I thought the seasoned substrate would be enough to have an instantly cycled aquarium. It was not, and I lost some fish.

[Mr Gumby]

On 1/10/2022 at 3:46 PM, HH Morant said:

Aquariumscience.org has some articles about the subject of beneficial bacteria. I am not sure exactly which article contains this information, but as I recall the author says that, even in a poorly filtered aquarium, 90% of beneficial bacteria is in the filter. This is because the beneficial bacteria need surface area and flow, and generally there is not enough flow in the aquarium to support large numbers of beneficial bacteria. I am not sure if the author cites any studies.

Under-gravel filters and powerheads aimed at the substrate would be exceptions to this rule because they create flow in the substrate.

The flow in the filter is what allows large numbers of beneficial bacteria to live there.

In 2020 I had an experience which makes me think this is correct. I bought a used aquarium with a used substrate, which I kept wet during the move of the aquarium. I thought the seasoned substrate would be enough to have an instantly cycled aquarium. It was not, and I lost some fish.

Interesting, I'll have a read through.

On a slight tangent I turned my filter off in my main display once the plants established and now just rely on air for water movement.

I found no spikes occurred and nitrate went down. I'm guessing the plants are taking up raw ammonia before the bacteria has a chance to convert it

[Patrick_G]

On 1/10/2022 at 7:27 AM, lefty o said:

anything in the tank with a surface for them to be on, is where they are. about the only thin in an aquarium that has little to no beneficial bacteria is the water itself.

From what I’ve read this is true.
 

In my bare bottom guppy colony it’s probably all in the sponge filters, in my 75 with lots of hardscape and plants it’s probably split between filter and surfaces and in my unfiltered tank it’s surely just on the surfaces since there is no filter. 

[Chad]

I've followed the guidance in aquariumscience.org as well. I highly recommend as a read and see for yourself if you think he's right. He says BB can live anywhere, but yes you need surface and flow. So if you don't have a filter, the BB will find a place to live as long as there is flow. Just not as efficiently as with a filter. Of course, time allows the BB to build up too.