just how much ben bacteria lives in the substrate?

[wesleydnunder]

The beneficial bacteria are spread throughout the aerobic portions of the aquarium; glass, substrate, scape, plants and filter. The size of the colony is dependent on the amount of food available... we all know this. Sand has probably the largest ratio of surface area to volume of all the substrates we use. This is why such a small volume of sand in a fluidized bed filter can handle the bioload of a large tank.

With enough surface area exposed to oxygenated water, additional biofiltration isn't necessary.

The fact that your tank didn't experience a cycle can probably be attributed to low stocking density coupled with a larger portion of the biobed living in the filter. When the available food exceeded what the bacteria in the filter could consume, they reproduced to meet the excess. Exact percentage the sand held? Who knows... any number given is pure speculation.

Mark

 

[MacMyers]

The beneficial bacteria are spread throughout the aerobic portions of the aquarium; glass, substrate, scape, plants and filter. The size of the colony is dependent on the amount of food available... we all know this. Sand has probably the largest ratio of surface area to volume of all the substrates we use. This is why such a small volume of sand in a fluidized bed filter can handle the bioload of a large tank.

With enough surface area exposed to oxygenated water, additional biofiltration isn't necessary.

The fact that your tank didn't experience a cycle can probably be attributed to low stocking density coupled with a larger portion of the biobed living in the filter. When the available food exceeded what the bacteria in the filter could consume, they reproduced to meet the excess. Exact percentage the sand held? Who knows... any number given is pure speculation.

Mark

:iagree:
Elegantly articulated.

 

[Khemul]

Agreed.

There is no set amount that lives in the sand and no safe way to measure it. It would depend on filter, maintenance, how often the media is replaced, bio-load, decorations in the tank, type of sand, depth of sand, and probably a few dozen other factors that we don't even know about. Basically for you it could have been 1%, for someone else it could be 50% (or even more) of the bio-filter.


In theory you could even 'train' the bacteria to live where you want. You simply make life difficult everywhere else. :evil_lol:

 

[BettaFishMommy]

The fact that your tank didn't experience a cycle can probably be attributed to low stocking density coupled with a larger portion of the biobed living in the filter.

Mark

i wouldn't say this tank has a low stocking density, lol. there's two big fish in there and they are messy messy! (oscar and a paratilapia polleni)

It would depend on filter, maintenance, how often the media is replaced, bio-load, decorations in the tank, type of sand, depth of sand, and probably a few dozen other factors that we don't even know about. Basically for you it could have been 1%, for someone else it could be 50% (or even more) of the bio-filter.

media has never been replaced on these filters, except for the polyester batting. rinsing always happens in tank water, never under the tap. decorations are two plastic resin wood pieces and two plastic plants (see avatar). decor has been rinsed/scrubbed under tap water on occasion.

i fully agree that other tanks may not have the same configuration of bacteria in the filter vs. bacteria on tank surfaces. this thread is in regards to my tank though, and the discussion between another fish keeper and myself on whether or not the ben bacteria in my tank took a hit or not.

 

[jetajockey]

nitrifying bacteria is going to be concentrated in the areas in which it thrives. While it can be present in any area with biofilm, it's not just evenly spread throughout the aquarium. I recall reading a study that stated that some species of nitrifying bacteria are motile. Does that mean that bacteria are walking around? No, but it tells me that they will go, and also be more fruitful in the areas that are most hospitable to them.

I think its safe to say that most aquariums do not have a consistent amount of flow through its entirety.

Would be kinda cool to test this by taking 2 new tanks, same bioloads in each, and then taking something like an ornament, or gravel from the established tank to put into one new tank, while in the other new tank you put some filter media from the established tank. Just to see if there is a difference in cycling time.

 

[spirofucci]

Agree with Mark although you most likley had a ton of good bacteria in the sand, your tank had enough elswhere to make up for the loss. Also, I think the main reason folks have bare bottom is that there is no place for the "poop" and uneaten food to stick to so there are far less nutrients for bacteria and algae to feed on.

 

[Optimus]

Hey bfm I too have a 55gal and would say confidently that in my aquarium the most minuscule amount of ben bacteria live in my substrate and here's why...

I never add dechlor to my aquarium until after I have completed the water change. I water change 40-50% weekly and since chlorine kills ben bacteria on contact I think it's safe to say very little if any ben bacteria survive in my substrate. I turn the filter off during the change and switch it back on roughly 15mins after I add the dechlor. By the way I have never had a spike *fingers crossed*

Optimus

 

[BettaFishMommy]

one thing i am looking forward to seeing is if the diatoms i would get constantly in this tank will stop appearing. my theory is that the silicates in the play sand were feeding the diatoms and causing outbreaks. when i removed the sand i took my 'sponge on stick' and wiped down all the tank walls to clear off the diatoms (i do this at every water change anyway). will be interesting to see if the diatoms come back or not (haven't seen them re-occur yet and usually they started creeping within a few days of a water change when the sand was in).

 

[Cerianthus]

Chlorine and Monochloramine may not kill BB on contact as one may assume, it always depend on their [conc] and if memory serves, nitrifiers may be more resistant to standard [Cl2], [NH2Cl] than other common pathogenic bacteria. Perhaps due to such reasoning, some may or may not experience problems after drastic changes/disturbances on well established tank. At least one the the reasons.

 

[excuzzzeme]

I don't believe there is a "one size fits all" answer to this. There are far too many variables that need to be accounted for. The very water itself can be a large determining factor when you try to answer. Next item would be the filtration. The amount of water flow and the amount of contact time with the air all play a role in it. Contact time with the air effects the O2 content which in turn will affect the aerobic bacteria colony. (When I mention filtration, this isn't in reference to mechanical or biological media). I have no bio-media as such in my filters which would place the role of colonization into my substrate (which is PFS).

As far as diatoms go, I find that phosphorus (?) or Phosphate, I don't remember which, has the greatest effect on them and has little to do with substrate. I have used sand as well as gravel without having a diatom bloom so I discount the silica as a sole reason for it.