Co2 and Ph

[Mmiller2001]

On 9/27/2022 at 7:49 AM, Minanora said:

I'm on my phone so I can't remove the quote.... But @AnimalNerd98 & @Mmiller2001

Does the carbonic acid and CO2 precipitate and break down into carbonate and bicarbonate? Do they actually raise pH?

While the CO2 is off, pH is higher. Without regular water changes can the pH get even higher due to CO2 injection?

I change water regularly on my injected tank and my water is liquid rock so it's hard to see what's going on long term.

Does the carbon go free and need to bind to something? What happens to it....

Chemical reaction.... And dissolution...

🤔

No, because of acids created in nitrification. Basically, other acids are present keeping a pH range.

https://www.2hraquarist.com/blogs/freshwater-fish-and-livestock/ph-swings-co2-injection?_pos=1&_sid=f0453ff19&_ss=r

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489657/

https://www.2hraquarist.com/blogs/ph-kh-gh-tds/kh-explained?_pos=10&_sid=f0453ff19&_ss=r

 

 

[AnimalNerd98]

On 9/27/2022 at 6:43 AM, PerceptivePesce said:

I'm out of questions. Maybe I'll come up with some after I digest this thread a bit. 

Somewhat related. I stumbled into a reddit thread where the big brains were hypothesizing about archaea being the beneficial organism in low pH tanks. They were saying something like bacteria can't live in lower pH, the bad kind nor the beneficial kind, and that archaea were responsible for doing the nitrogen cycle conversion stuff.  Something like that, I def could be recalling wrong.  Twas interesting tho

Haha, the Pac-Man joined with the smiley face is just bicarbonate. Bicarbonate is just a carbonate molecule combined with a single proton. 

Hmm, interesting ideas. I know that extremophile archae exist at low pHs, but I am not sure if they undergo the process of nitrification. After doing a little digging, I asked myself: why can’t nitrifying bacteria adapt or evolve to lower pHs over time across several generations? I think the answer lies in the chemistry. At pHs lower than 6.5, the dominant form of ammonia (NH3) is actually ammonium (NH4+). The enzymes that nitrifiying bacteria normally use may not bind to ammonium as well as ammonia. Interesting stuff indeed! 

[AnimalNerd98]

On 9/27/2022 at 7:49 AM, Minanora said:

I'm on my phone so I can't remove the quote.... But @AnimalNerd98 & @Mmiller2001

Does the carbonic acid and CO2 precipitate and break down into carbonate and bicarbonate? Do they actually raise pH?

While the CO2 is off, pH is higher. Without regular water changes can the pH get even higher due to CO2 injection?

I change water regularly on my injected tank and my water is liquid rock so it's hard to see what's going on long term.

Does the carbon go free and need to bind to something? What happens to it....

Chemical reaction.... And dissolution...

🤔

1) Carbonic acid is in an equilibrium with the amounts of bicarbonate and carbonate. The carbonate and bicarbonate do not have a direct effect on pH, they just act as buffers against large pH changes. 
 

2) When CO2 is off, the pH goes up because less carbonic acid is being formed. This “raised” pH is just the normal pH of your aquarium water without injecting CO2, it will not get any higher without any additives or changes. If you are changing water regularly, you are likely keeping the water from actually becoming too acidic (below 6.5). 

3) The carbon dioxide can either gas off into the air or it can react with water to form carbonic acid. 

[PerceptivePesce]

On 9/27/2022 at 10:42 AM, AnimalNerd98 said:

Haha, the Pac-Man joined with the smiley face is just bicarbonate. Bicarbonate is just a carbonate molecule combined with a single proton. 

teehee, this image is also the official chemical equation for the process of me digesting info and coming up with more Qs. 😊

[modified lung]

On 9/27/2022 at 5:43 AM, PerceptivePesce said:

Somewhat related. I stumbled into a reddit thread where the big brains were hypothesizing about archaea being the beneficial organism in low pH tanks. They were saying something like bacteria can't live in lower pH, the bad kind nor the beneficial kind, and that archaea were responsible for doing the nitrogen cycle conversion stuff.  Something like that, I def could be recalling wrong.  Twas interesting tho

Archaea are the major nitrifiers in mature aquariums regardless of pH because they do better than bacteria when ammonia levels are as low as we want. In new-ish cycled aquariums there's more bacteria just because they grow a lot faster than archaea.

Nitrifying bacteria can live and work in very low pH with some time to adapt but they would need to be continually micro-dosed with bicarbs to reproduce and keep the population going. Most of us aren't going to do that so that fact is kind of irrelevant.

 

On 9/27/2022 at 6:49 AM, Minanora said:

While the CO2 is off, pH is higher. Without regular water changes can the pH get even higher due to CO2 injection?

This will only happen if there's something in the water consuming enough HCO3- (bicarbonate). Then to keep the equilibrium, CO3- (carbonate) will steel an H+ from H2O which makes HCO3- and free OH-.

CO3- + H2O = HCO3- + OH-

The new free OH- raises the base pH of your water.

But the pH will only rise so far if you have calcium in your water because at a certain pH the Ca+ will start binding to CO3- and precipitate where it can't make any more OH-.

If there's no Ca+, then the base pH of your water can just keep going up. But something like this will only happen to any significant degree if you have a greenwater bloom or waaayy too many plants. My outdoor 100 gal stock tank almost hits 10 pH because it's packed with so many plants a fish wouldn't be able to swim around if it tried and rarely gets water changes (there's no fish in it btw).

[Minanora]

On 9/27/2022 at 10:51 AM, modified lung said:

Archaea are the major nitrifiers in mature aquariums regardless of pH because they do better than bacteria when ammonia levels are as low as we want. In new-ish cycled aquariums there's more bacteria just because they grow a lot faster than archaea.

Nitrifying bacteria can live and work in very low pH with some time to adapt but they would need to be continually micro-dosed with bicarbs to reproduce and keep the population going. Most of us aren't going to do that so that fact is kind of irrelevant.

 

This will only happen if there's something in the water consuming enough HCO3- (bicarbonate). Then to keep the equilibrium, CO3- (carbonate) will steel an H+ from H2O which makes HCO3- and free OH-.

CO3- + H2O = HCO3- + OH-

The new free OH- raises the base pH of your water.

But the pH will only rise so far if you have calcium in your water because at a certain pH the Ca+ will start binding to CO3- and precipitate where it can't make any more OH-.

If there's no Ca+, then the base pH of your water can just keep going up. But something like this will only happen to any significant degree if you have a greenwater bloom or waaayy too many plants. My outdoor 100 gal stock tank almost hits 10 pH because it's packed with so many plants a fish wouldn't be able to swim around if it tried and rarely gets water changes (there's no fish in it btw).

I checked my water today. I missed last week's water change. I usually change 75% weekly. pH last week at lowest co2, 7.8 today, 8.2.

 

On 9/27/2022 at 10:30 PM, Minanora said:

I checked my water today. I missed last week's water change. I usually change 75% weekly. pH last week at lowest co2, 7.8 today, 8.2.

 

Maybe it's been two weeks.... I left my planner at work today