Is it low ph or lack of kh that causes 'low ph' bacteria to grow ?

[anewbie]

I think this has probably be answered before but maybe not - is it the actual ph that triggers the type of bacteria that grows for nitrification or is it the water chemistry and lack of kh/ions that causes this change in bacteria. I.e, if i pump in a lot of co2 into 8.5 water i doubt it will change the bacteria type despite having a ph of 5.5 but if i artifically push the ph up without changing the kh/ion level would the 'low' ph bacteria still grow in the water due to lack of ions via tweaking the co2 or using sodium carbonate.

 

[dw1305]

Hi all,

I think this has probably be answered before but maybe not - is it the actual ph that triggers the type of bacteria that grows for nitrification or is it the water chemistry and lack of kh/ions that causes this change in bacteria. I.e, if i pump in a lot of co2 into 8.5 water i doubt it will change the bacteria type despite having a ph of 5.5 but if i artifically push the ph up without changing the kh/ion level would the 'low' ph bacteria still grow in the water due to lack of ions via tweaking the co2 or using sodium carbonate.

<"https://apistogramma.com/forum/thre...er-aquarium-nitrogen-cycle.30016/#post-136365">.

We have a number of threads on UKAPS, where we've talked with scientists involved in research on nitrification in aquaria. I'll link a couple in, but basically it isn't something you have to worry about.

This is the most up to date we have, Josh Neufeld is actually a cichlid keeper -
<"https://www.ukaps.org/forum/threads...the-sequence-of-microbial-colonisation.79329/">

This one links into a number of threads.

<"https://www.ukaps.org/forum/threads/tank-on-back-order-plans-going-a-bit-wrong.78790/#post-791784">

Cheers Darrel

 

[dw1305]

Hi all,
I should have also said that, even if you did want to add some dKH (and I don't see any reason why you need to), sodium (bi)carbonate is a very poor choice for this, potassium (bi) carbonate is a better choice, and if you have hard tap water? A splash of that is ideal.

Cheers Darrel

 

[anewbie]

Hi all,

<"https://apistogramma.com/forum/thre...er-aquarium-nitrogen-cycle.30016/#post-136365">.

We have a number of threads on UKAPS, where we've talked with scientists involved in research on nitrification in aquaria. I'll link a couple in, but basically it isn't something you have to worry about.

This is the most up to date we have, Josh Neufeld is actually a cichlid keeper -
<"https://www.ukaps.org/forum/threads...the-sequence-of-microbial-colonisation.79329/">

This one links into a number of threads.

<"https://www.ukaps.org/forum/threads/tank-on-back-order-plans-going-a-bit-wrong.78790/#post-791784">

Cheers Darrel

I don't think you understand the question or maybe i don't understand the answer. I'm not worry about the bacteria forming and i don't really want to change the ph but it was more hypothetical - is it the water chemistry or the ph - it goes back to the old comment if i have water hardness enough to have a ph of 8.5 and i pump in a ton of co2 to lower the ph to 5 - would that change the type of bacteria forming or would the same type of bacteria form in the water even though the ph has dropped (i.e, is ph meaningless or is it a way of guess the carbonate level that is very in accurate since day/night cycles can easily change the co2 level).

 

[dw1305]

Hi all,

I don't think you understand the question or maybe i don't understand the answer.

The former.

I'm not worry about the bacteria forming and i don't really want to change the ph but it was more hypothetical - is it the water chemistry or the ph - it goes back to the old comment if i have water hardness enough to have a ph of 8.5 and i pump in a ton of co2 to lower the ph to 5 - would that change the type of bacteria forming or would the same type of bacteria form in the water even though the ph has dropped

In an established set-up you will get a very diverse assemblage of nitrifying organisms, which will change in abundance dependent upon the ammonia loading, amount of dissolved oxygen, carbonate hardness etc.

This is discussed in the Barthelme et al. paper in <"https://www.ukaps.org/forum/threads/everyone-is-right.66212/page-2#post-655938">.

(i.e, is ph meaningless or is it a way of guess the carbonate level that is very in accurate since day/night cycles can easily change the co2 level).

There may not actually be a scientific paper that has looked at the effect of raised CO2 levels, in planted tanks, on the microbial assemblage of nitrifying organisms.

Because "plant/microbe" nitrification is potentially an order of magnitude more efficient than "microbe only" nitrification, added CO2 isn't a variable that noticeably effects fixed nitrogen levels, but it would be difficult to untangle exactly why.

Because adding CO2 doesn't change the carbonate hardness, it just changes pH (because the carbonate ~ CO2 ~ pH equilibrium is tilted by the extra H2CO3) I'm going to say it doesn't make any difference, but that would be "best guess".

I'll see what I can find tomorrow.

Cheers Darrel

 

[anewbie]

Hi all,

The former.

In an established set-up you will get a very diverse assemblage of nitrifying organisms, which will change in abundance dependent upon the ammonia loading, amount of dissolved oxygen, carbonate hardness etc.

This is discussed in the Barthelme et al. paper in <"https://www.ukaps.org/forum/threads/everyone-is-right.66212/page-2#post-655938">.

There may not actually be a scientific paper that has looked at the effect of raised CO2 levels, in planted tanks, on the microbial assemblage of nitrifying organisms.

Because "plant/microbe" nitrification is potentially an order of magnitude more efficient than "microbe only" nitrification, added CO2 isn't a variable that noticeably effects fixed nitrogen levels, but it would be difficult to untangle exactly why.

Because adding CO2 doesn't change the carbonate hardness, it just changes pH (because the carbonate ~ CO2 ~ pH equilibrium is tilted by the extra H2CO3) I'm going to say it doesn't make any difference, but that would be "best guess".

I'll see what I can find tomorrow.

Cheers Darrel

Ok; thanks. The key point i'm trying to ask is ph relevant to anything or is it just a way of guess the carbonate (kh) hardness and should all tests ignore ph and focus on kh.

 

[MacZ]

Both will have impact, I think. I would assume it is theoretically possible that there are bacteria strains that might work well with low pH (however it is achieved) with high KH, while there are also such that do better with high pH/high KH, low pH/low KH and high pH/low KH. All combinations are possible, all should have strains that will do better then, than in another conbination.

 

[dw1305]

Hi all,

Ok; thanks. The key point i'm trying to ask is ph relevant to anything or is it just a way of guess the carbonate (kh) hardness and should all tests ignore ph and focus on kh.

I think that when you add CO2 it is the only time that you decouple carbonate hardness and pH.

Carbonate hardness, as acid neutralising capacity, is really what we are interested in. I actually just use conductivity as a proxy measurement, I can do this because I know the majority of ions, in my water, will be Ca++ and 2HCO3- ions.

I would be extremely surprised if there aren't nitrifying microbes adapted to high CO2 levels, partially because there have been Geological time periods when atmospheric CO2 levels were higher.

Cheers Darrel