low pH & bacteria

[Ghazanfar Ghori]

How do nitrifying bacteria respond to a pH crash or low pH? Do
they die off completely?

 

[Ghazanfar Ghori]

Actually I just did a google search. The information is a cause for
concern...

http://www.bioconlabs.com/nitribactfacts.html

I understand that at low pH ammonia toxicity is reduced, so that
may help. At a constant pH of 4 or so it probably isn't long
before the bacteria die off.

Still researching....

 

[Neil]

Ghazanfar,
Interesting piece and topic.
I have kept too many tanks at a very low pH for too long for nitrification to not be taking place. Water changes alone would not mitigate the amount of ammonia in the system, regardless of the decreased toxicity! The articl says that the two types of bacteria cannot withstand extreme ranges of pH, but it also says that there are many species of each. I suspect that a sustained lower pH wouldeventually produce bacteria capable of withstanding the environmental conditions they have been subjected to. Afterall bacteria is about the only thing that is living in active volcanos, etc. They are surely a diverse enough critter to "spout" colonies resilient enough to withstand 4.0pH.
Regardless, soft-water Dwarf Cichlids can often easily handle similar pH ranges and even can survive pH crashes in the low 3s and high 2s. The fins start disolving, but the animals often survive. I am obviously speaking from experience here, although not particularly proud of knowing about it first hand!
Neil

 

[farm41]

Really, PH 2, I didn't know that anything would live at that extreme. How long was it that low?

 

[tjudy]

Nitrosomonas and Nitrobacter are two genera of bacteria that contain many species. They are not the onlt genera involved either. I have never noticed a problem with ammonia or nitrite spikes after a period of low pH.

 

[Ghazanfar Ghori]

At a low pH ammonia toxicity is reduced as its predominatly
present as NH4+ and not the toxic NH3+. Maybe that's why it
won't show up on a test kit. It would be interesting to see
do a simple experiment. Take a sample of water from a fish
tank thats been at low pH and add a little baking soda to raise
the pH and then test from that sample for ammonia.

Still researching this topic via google. I'll let you guys know if
I find something conculsive.

 

[Ghazanfar Ghori]

Another interesting link...

http://ce.ecn.purdue.edu/~piwc/w3-research/free-ammonia/nh3.html

Check with pH 7 and then pH 4 - HUGE difference.

 

[Ghazanfar Ghori]

More reading....

http://members.aol.com/bgdiscus/ph.htm

 

[Ghazanfar Ghori]

Sorry about all the posts....

Just read something that shows the chemical process behind
the nitrogen cycle.

...without alkalinity in the water biological filtration surely dies

http://cyberfins.minidns.net/articles/docc/equations for biological filtration.shtml


This should be enough to read and research through the weekend.

 

[aspen]

there's an article on this page called 'how low can you go', which describes an experiment and some other findings by randy carey, a highly respected and published author and breeder of tetras and cichlids.

http://www.characin.com/carey/articles/

if there is no nitrification occurring at these low ph's, as low as 2.9, how did the fry survive? maybe nitrification is not happening the same as at other ph levels, but the mere survival of fish, let alone the tiny fry indicates that the waste is being de-toxified by some mechanism.

rick

p.s., good subject for discussion, certainly one of the most important aspects of keeping fish imo.