# How long do Aerobic Bacteria surivive without food



## Fishy_Cichlid (Aug 4, 2011)

Many of us have cycled hospital tanks. And often these tanks are empty. *I would like to know if any actual research has been done to find out how long the Nitrifying bacteria would survive without addition of Ammonia in any form. *Members who have been keeping hospital tanks or with similar experience could also chip in.

I found this article but would like to know from 1st hand experience of the members here.
http://www.practicalfishkeeping.co.uk/c ... p?sid=4780


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## Mr.Dempsey (Jan 4, 2012)

*** heard about a week or 2, but Most people will run sponge filters in hospital tanks and just run the sponge in another tank or sump and just take it out when needed.


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## Fishy_Cichlid (Aug 4, 2011)

Seems like even research too in this area fails to give a unanimous decision on the decay rates. However, its clear that decay rates are low for aerobic nitrifying bacteria. One reasearch says its around 5-12% per day for non-active nitrifiers. This implies that the entire colony will be reduced to the following % in ---- no. of days if decay is at 12%.
50% - 5 days
25% - 11days
1% - 36 days
However, the reasearch is based on the inference from Heterotrophics rather than actually measured for Nitrifiers.

The decay rate has been seen to exponentailly decrease over time. Depending on temperature, the degradation of a heterotrophic biomass is between 2 - 4 weeks.

Some references i referred to :
http://theaquariumwiki.com/PDF/CES-240.pdf
http://onlinelibrary.wiley.com/doi/10.1 ... 2/abstract 
http://www.wastewaterhandbook.com/docum ... netics.pdf
http://www.sciencedirect.com/science/ar ... 2408002009
http://www.springerlink.com/content/u63351008711x464/
http://www.sciencedirect.com/science/ar ... 2408002009


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## t.trezona (Feb 26, 2012)

Some bacteria can survive indefinitely. They may just set there and do nothing until a required substrate returns to them. Bacteria are usually limited in terms of one or more substrates required for growth. When it is available they grow. When not they just stop growing. When it returns they begin growing again.


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## AfricanLove (Jan 2, 2012)

Fishy_Cichlid said:


> Many of us have cycled hospital tanks. And often these tanks are empty. *I would like to know if any actual research has been done to find out how long the Nitrifying bacteria would survive without addition of Ammonia in any form. *Members who have been keeping hospital tanks or with similar experience could also chip in.
> 
> I found this article but would like to know from 1st hand experience of the members here.
> http://www.practicalfishkeeping.co.uk/c ... p?sid=4780


Could just add a pleco or some kind of catfish


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## Number6 (Mar 13, 2003)

*Fishy_Cichlid*
the ideal bacteria for our tanks have an amazing tolerance for starvation... this is why you won't ever find a single answer... and many a tank can be dirtier than you'd ever imagine so I've had tanks stay "cycled" for two months running empty and heated... who knows if it would have ever died out. I added fish, so...


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## Fishy_Cichlid (Aug 4, 2011)

> Some bacteria can survive indefinitely. They may just set there and do nothing until a required substrate returns to them. Bacteria are usually limited in terms of one or more substrates required for growth. When it is available they grow. When not they just stop growing. When it returns they begin growing again.


Heterotrophic Bacteria form spores, so they are able to remain dormant for a longer period of time. Take for ex. most of the branded bacteria sold in the market.

*Number6*
But does adding fish in a tank 2 months after cycling and without addition of Ammonia in the intervening period create a "New Tank Syndrome" ? Wish there were more empirical data so that hobbyists could get an approximate idea.


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## Number6 (Mar 13, 2003)

*Fishy_Cichlid*
no, after two months of empty, the addition of fish resulted in 0 measurable ammonia and nitrite. Now, I have heard of ammonia spikes in hospital tanks after only 3 weeks of being empty, so I really think there are a large number of factors that would contribute to the time to starve for the bacteria. Forget empirical data, hard to come up with any practical data when the factors at TNC (to numerous to count). 
:lol:


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## vann59 (Jun 20, 2011)

This is a good question even if it doesn't have a definite answer. Of course a dry tank and media would no doubt be different that ones kept wet.

For this reason, I have made a habit of using a filters with interchangeable media. For instance a penguin 350 takes the same size bio wheel as a model 200, so you can swap out one from the 350 to the 200 as donor media, provided the donor tank has enough total media. Hospital tanks usually don't have a large bio load so that helps.

It makes sense to keep plenty of media in any bulk media filter for this very purpose.


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## prov356 (Sep 20, 2006)

> Forget empirical data, hard to come up with any practical data when the factors at TNC (to numerous to count).


 :thumb: What's the practical application? I don't see many members here struggling with this. If a tank sits empty of fish, add a bit of ammonia to test. You'll know.


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## Number6 (Mar 13, 2003)

prov356 said:


> :thumb: What's the practical application? I don't see many members here struggling with this. If a tank sits empty of fish, add a bit of ammonia to test. You'll know.


I agree... that's the safe and smart approach...


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