# How does bacteria die ?



## gklaw (May 31, 2010)

Okay, I keep hearing that bacteria die if power fail. My memory of high school biology some 30 years ago tells me that bacteria do not die.

The can stop growing and become dormant unless we do specific things to terminate them: UV, germicidal chemical, etc.

If this is correct, then when a filter is shut down for days, the bacteria culture stays dormant. Yes, the water fouls up and smell - unless this will kill the bacteria. When I want to restart the filter, I just rinse it well to get rid of the foul water.

Cold or water water also does not kill bacteria? At 60 - 70 C, it takes 30 minutes to kill bacteria.

Any biologist out there to enlighten this topic ?

Another point is how long can bacteria stay dormant? My theory is that I can use old media that has been stored for months to jump start the biological cycle. Is this how products like "Cycle" work?


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## tony1928 (Apr 22, 2010)

Nice topic. I'm dying to know as well. If your theory is true, then the only die off would start to happen as the nutrient supply dwindles.


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## Rastapus (Apr 21, 2010)

Bacteria require a food source. At least the bacteria in an aquarium filter. With no Ammonia and or Nitrite, the different types of bacteria will die. Weather they are dormant or dead I am unsure but to my knowledge, they die. If they are dormant they would still need to repopulate the filter to a healthy state. I don't see an advantage to using old media that has been sitting around.


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## rescuepenguin (Apr 21, 2010)

Knowledge of bacteria is required for my job, plus I have had formal education on the subject too.

Bacteria can and does die. As Rastapus has stated, it will die from lack of food or a condition that will kill it. An example of this is very high heat. The conditions required to kill bacteria vary from species to species, but lack of food will always kill bacteria.

With regards to being dormant, this usually happens when conditions get hostile but not fatal. An example of this would be low temperatures. This is why you keep food refrigerated. The bacteria slows down and multiplies at a much slower rate. When you freeze it, some bacteria species will die, but most will become dormant until thawed out again, then will start multiplying again.

As a rule, the higher the temperature the faster it will multiply. With some species found in our food, a colony can double its size in 20 mins. on a hot summer day. The general rule is to keep food below 4 C.

For the media, I don't see an advantage, the bacteria is probably dead. The key is food and surface area in your aquarium, a warmer temperature (don't go overboard here) will help too.

I hope this helps


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## Fish Whisper (Apr 22, 2010)

*Hmmmm i think this is what happens...*

Remember bacteria are not all the same, the bacteria in your filter 
have been conditioned, 
1. to thrives at nitrifying in a aerobic condition 
2, at a given temperature,

As soon as you pull the plug the condition changes, and there is a shock effect

Firstly they loss their food supply so their dying faster than they are reproducing, plus other colonies of bacteria that don't necessarily nitrify can start to out produce the nitrifying bacteria (the anaerobic ones that create the bad smell)

Sooo essentially ur starving them and then your letting them get beaten up by the bad bacteria.


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## discuspaul (Jul 2, 2010)

Aquatic nitrifying bacteria require not only food, but some oxygen and some amount of water circulation (to bring the food to them, inter alia), and stability of other elements as pointed out earlier. Without these elements, after EXTENDED periods of time, (more than hours) they will begin to perish. I wouldn't risk trying to kick-start a cycle with filter media that has been sitting around stagnant & dormant for days.
As for Stability, Safe-Start, Cycle, and other products, while not stated on the containers, I expect they are biologically treated with some form of additive which permits a dormancy stage for a certain period of time without these elements being present, and which enables them to revive, or come out of dormancy, when re-introduced into an environment that does contain food, oxygen, etc.


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## JohnnyAppleSnail (May 30, 2010)

I was able to kick start a Cycle for a 125 gal Tank with no problems with Filter Media that had been sitting in Buckets for about 2+ weeks,when a Large Tank of Mine sprung a Leak I had to order a New Tank,in the meantime I was told to put My existing Filter Media in Buckets of Water and to make sure it was emersed. When I went to Cycle New Tank and put the Old Media back in My Filters (Yes,it was Smelly) the outcome was near Perfect,I ran the Filter System for a few days added as much of the existing Tank water the Fish were already in then added the Fish. The Parameters were excellent never lost a Fish. I was told to do this by an accomplished Aquarist and it sure the heck worked and made everything so much easier to start New Tank!


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## giraffee (Mar 28, 2011)

My uneducated 2 cents from today's research on power outage - bacteria must have access to oxygen and be submerged (I'm sure everyone knew this but me anyways). If the media dries out - the bacteria dies. That also would mean that if you start your filter with the dead bacteria in it would poison your fish... This is the link that I found useful - When the Power Fails -- Aquarium maintenance --> scroll down to 4)


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## neven (May 15, 2010)

for those with hang on back filters if the power fails, make sure it doesn't back siphon into the tank. I always make sure i load up the filter with water during maintenance since i easily can get distracted and take too long (or have to go out in the middle of it)


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## punchbuggy (Apr 21, 2010)

really depends on the type of bacteria. there are aerobic ones.. there are anaerobic ones. the bacteria that convert NH3 -> NO2 require oxygen. If you don't have oxygen this process won't occur, which is bad for your tank since you'll have an ammonia spike AND bad for the bacteria since that process produces energy for them to live. 

Some sporulate too, but I don't think these ones do.. 

Either theyre dead, dormant, in spore form, without oxygen for awhile they are going to get unhappy. When they are unhappy your tank will be unhappy.


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## AWW (Apr 22, 2010)

rescuepenguin said:


> As a rule, the higher the temperature the faster it will multiply. With some species found in our food, a colony can double its size in 20 mins.


How much does the temperature actually affect the bacteria In higher ranges? 
Would you have a harder time working up a good culture in a cold water tank? (65 - 70f). 
And, In warmer tanks, Does it help the bacteria if you have a warmer temperature than a lower one? I keep my tanks at around 82, Would bumping it up to 87 or so help at all?


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## gklaw (May 31, 2010)

Thank you all for the input.



AWW said:


> And, In warmer tanks, Does it help the bacteria if you have a warmer temperature than a lower one? I keep my tanks at around 82, Would bumping it up to 87 or so help at all?


The only problem I have with this approach is the higher temp also speed up decompose process for waste. The fish may also eat more (assuming that one will feed more) and generate more waste ?


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## AWW (Apr 22, 2010)

gklaw said:


> The only problem I have with this approach is the higher temp also speed up decompose process for waste. The fish may also eat more (assuming that one will feed more) and generate more waste ?


True, But, more feed, more growth, more poop, more bacteria? Whats not to love?


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## rescuepenguin (Apr 21, 2010)

AWW said:


> How much does the temperature actually affect the bacteria In higher ranges?
> Would you have a harder time working up a good culture in a cold water tank? (65 - 70f).
> And, In warmer tanks, Does it help the bacteria if you have a warmer temperature than a lower one? I keep my tanks at around 82, Would bumping it up to 87 or so help at all?


That temperature difference probably won't make a lot of difference. I would keep your aquarium(s) at the temperature required for the species you are keeping. 82 is already on the high end, I don't see a need to bump it up to 87.


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## AWW (Apr 22, 2010)

Yeah, I didnt think it would make difference  Just making sure


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## kelownaguy (Jan 1, 2011)

AWW said:


> How much does the temperature actually affect the bacteria In higher ranges?
> Would you have a harder time working up a good culture in a cold water tank? (65 - 70f).
> And, In warmer tanks, Does it help the bacteria if you have a warmer temperature than a lower one? I keep my tanks at around 82, Would bumping it up to 87 or so help at all?


Twice as hard,apparently.
Inhibition by low/high pH is something to consider too.

"Temperature

The temperature for optimum growth of nitrifying bacteria is between 77-86° F (25-30° C).

Growth rate is decreased by 50% at 64° F (18° C).

Growth rate is decreased by 75% at 46-50° F.

No activity will occur at 39° F (4° C)

Nitrifying bacteria will die at 32° F (0° C).

Nitrifying bacteria will die at 120° F (49° C)

Nitrobacter is less tolerant of low temperatures than Nitrosomonas. In cold water systems, care must be taken to monitor the accumulation of nitrites.

pH

The optimum pH range for Nitrosomonas is between 7.8-8.0.

The optimum pH range for Nitrobacter is between 7.3-7.5

Nitrobacter will grow more slowly at the high pH levels typical of marine aquaria and preferred by African Rift Lake Cichlids. Initial high nitrite concentrations may exist. At pH levels below 7.0, Nitrosomonas will grow more slowly and increases in ammonia may become evident. Nitrosomonas growth is inhibited at a pH of 6.5. All nitrification is inhibited if the pH drops to 6.0 or less."

From Nitrifying Bacteria Facts


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