Bacteria In Gravel?

[doktor doris]

hiya all,

Do useful amounts of bacteria live in gravel, if the tank doesn't have an under-gravel filter?

ta

doris

the reason I want to know is I have read that one shouldn't vacuum all the gravel at once to avoid wiping out bacteria.

 

[Bebobb]

I vaccume my gravel, and my fish do fine...

 

[drobbyb]

No significant amount of nitrifying bacteria live in the gravel. You can gravel vac as much as you want and it won't hurt anything.

 

[doresy]

Hi, always worth checking but in this case no worthwhile bacteria in the gravel unless an under gravel filter is being used.

Basically, the required bacteria to have your filter cycled needs 2 elements, ie food and oxygen. Food in the form of ammonia from rotting food and fish waste and oxygen provided in the water flow. Gravel gets a load of food/fish waste but has no flow of water through it so no oxygen flow therefore not sustaining a beneficial bacteria growth.

Gravel vaccing is required to rid the gravel of bacteria that could cause infection to fish, especially bottom feeders like Cory.

This is not a scientific explanation but will give you a rough answer to your question

 

[doktor doris]

Thanks everyone, I thought the gravel had no useful levels in a non UGF tank.

All my books assert that one shouldn't vacuum gravel, but they are old, published in the days when an UGF was the norm.

cheers

doris

 

[Dave Spencer]

Planted tanks can have a significant amount of bacteria in the substrate due to a symbiotic relationship with the bacteria at the plant roots. A lot of planted people take the mulm from the bottom of an established tank to kick start a new one to get lots of healthy root growth from the start.

Dave.

 

[aaronnorth]

No significant amount of nitrifying bacteria live in the gravel. You can gravel vac as much as you want and it won't hurt anything.

who has tested that?
Have you got any papers?

Thanks. Aaron.

 

[drobbyb]

Well, in my 15 years of experience, I have never had a problem with gravel vaccing frequently. Therefore experience tells me that it is harmless in a modern tank using modern equipment except for planted tanks as you don't want to disturb the roots.

 

[Bignose]

Every surface in the tank grows a biofilm, too. This is a combination of bacteria and algae and fungus and all sort of microorganisms. This is just a consequence of having life in your tank, and is all in all a good thing. It is the main reason established tanks have fewer problems than new tanks, because if something like a filter slows down on a mature tank, the bacteria in the biofilm can take up some of the slack the bacteria in the filter aren't able to do any more. Mature tanks can survive several days without electricity primarily from a mature biofilm. Biofilm also provides food fro very young fry, as the fry consume microorganisms. Some fish, like plecos and oto catfish also consume biofilm.

But the biggest thing a biofilm does is introduce biodiversity into the tank. The idea is simple in that if you have a wide variety of microorganisms growing, then no one species of microorganism can become dominant. That is, if a bacteria that would cause problems should happen to get introduced, it won't be able to multiply super rapidly and cause problems because of all the other microorganisms in there. They are all competing with one another, and no one kind or species ever becomes dominant because of the competition.

Here is a good deal of more information about the biofilm: http/www.skepticalaquarist.com/docs/biofilm/devbio.shtml