# Ph drop and bacteria



## eduard (25 Mar 2014)

Hello, I'd like to ask about ph 'swings' in hi tech tank.My water is pH 6.8 dropping down to 5.6 on lights on.Are bacteria affected by this swing?


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## pepedopolous (25 Mar 2014)

Bacteria are some of the toughest mothers around. They live everywhere on earth, even where no other life can exist. Sure they might be affected somehow by a pH change but affected negatively? I doubt it. Just make sure that your fish are OK when the pH is at it's lowest.


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## eduard (26 Mar 2014)

Thanks for a quick response. Fish seems to be fine.Neons and glowlights are trying to breed. Otos are not as active.


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## Edvet (26 Mar 2014)

Don't worry about the Ph drop, in fact we use it to see if we give enough CO2 and strive for a full point drop to even a drop of 2-3 points in very soft water. Since it's a weak acid effect it won't bother the inhabitants.


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## eduard (26 Mar 2014)

Thanks again. I am doing full ph profile today.


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## EnderUK (26 Mar 2014)

I think eduard is more concerned, as I was at one point, of nitrifying bacteria shutting down below a PH of 5 therefore ammonia and nitrite not being converted. I have no idea if this is true or not. I assume that if you have good plant growth then the plants will absorb the NH3 and NO2 during the day at low ph and during the night when you stop the co2 the ph will begin to rise again and the bacteria will start performing their function again.


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## Edvet (26 Mar 2014)

If you have a large plant mass, i would never worrie about amonium or nitrite, plants eat that sh*t


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## dw1305 (26 Mar 2014)

Hi all,





EnderUK said:


> I assume that if you have good plant growth then the plants will absorb the NH3 and NO2 during the day at low ph and during the night when you stop the co2 the ph will begin to rise again and the bacteria will start performing their function again.


 I don't think you need to worry at all about the drop in pH when you add CO2, it is just changing the carbonate ~ CO2 (H2CO3) equilibrium, not the water chemistry. 

The nitrifying bacteria/archaea are chemoautotrophs utilising CO2 and oxygen to oxidise NH3 and produce energy (NH3 is the "electron donor"). As long as they have enough oxygen and a carbon source, nothing else really matters to them. 





Edvet said:


> f you have a large plant mass, i would never worrie about amonium or nitrite,


 I wouldn't either, a large plant mass trumps nearly all the other biological filtration options., what ever the question is "plants" or "more plants" is nearly always the answer.

cheers Darrel

.


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## eduard (26 Mar 2014)

Thank you very much.I'll find something else to worry about


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