Carbocalcium and pH

[Spare time]

I was wondering if anyone has run into lower pH issues when using something like all for reef or carbo calcium. I currently am having a lower pH issue (7.98 on my calibrated hand held pH tester) that I did not have before and I am not sure if it is related to switching to the DIY all for reef. I am concerned about carbo calcium producing bicarbonate and co2 and no carbonates, thereby lowering pH as well as making the production of calcium carbonate more costly to the corals. I am currently planning on getting a co2 scrubber to hook up to a nano skimmer in an attempt to solve this as I would rather not dump out my all for reef (which to my dissapointment has actually not been able to keep up with potassium and iodine (salifert kits) which had been stable when I dosed the red sea trace potassium and iodine (sparingly)+chaetogo+seachem reef builder+red sea calcium.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, it will tend to lower pH a little bit, where other supplements you may have switched from may tend to raise pH (carbonate or hydroxide).

 

[Spare time]

I may try my old dosing routine when I am done with this container to see if I potentially had an error in calibrating my pH meter when I used it last on my old dosing setup.

 

[Shooter6]

Did you read this before coming to that conclusion?
"CARBOCALCIUM - Tropic Marin®" https://www.tropic-marin-smartinfo.com/en/minerals/carbocalcium.html

 

[Shooter6]

"Carbocalcium question | REEF2REEF Saltwater and Reef Aquarium Forum" https://www.reef2reef.com/threads/carbocalcium-question.188449/

 

[Randy Holmes-Farley Verified Community Expert]

Did you read this before coming to that conclusion?
"CARBOCALCIUM - Tropic Marin®" https://www.tropic-marin-smartinfo.com/en/minerals/carbocalcium.html

Are you asking me?

Are you asserting that it does not lower pH? You base that on what? Look deeper than a simplistic interpretation of manufacturer claims...

The claim by Tropic Marin that it does not provide excess CO2 is strictly correct, but potentially misleading if people interpret that to mean it doesn't lower pH. The fact that pH "remains stable" is worded in a way that is not really claiming it is not stable at a lower level, just like one gets from a CaCO3/CO2 reactor where it is stable but at a lower level than if using continuous dosing of carbonate for alkalinity.

Let's look at formate metabolism to release carbonate:

2HCO2- + O2 --> 2CO3-- + 2H+

Thus, it forms carbonate that is consumed in calcification, and it adds H+, lowering pH. Now way around that.

But if it does so at a slow rate over time, the pH drop on dosing is not immediately noticed, and it might be claimed to be stable.

 

[Shooter6]

Are you asking me?

Are you asserting that it does not lower pH? You base that on what?

The claim by Tropic Marin that it does not provide excess CO2 is strictly correct, but potentially misleading if people interpret that to mean it doesn't lower pH.

Let's look at formate metabolism to release carbonate:

2HCO2- + O2 --> 2CO3-- + 2H+

Thus, it forms carbonate that is consumed in calcification, and it adds H+, lowering pH.

Yes i suppose i am
I dose 240ml of afr daily on my current system and have not suffered lowering of my ph.
I switched from redsea 3 part. The 3lb powder containers.

240ml on a 270gal system.

What size system are you using it on that your seeing significant ph drop?

On my current build, 1200-1400gal system im planning on using a combination of afr and kalkwaser, i found out afr powder is available in 33lb containers via special order.

Is the drop in ph your experiencing more significant compared to a calcium reactor?

 

[Randy Holmes-Farley Verified Community Expert]

Yes i suppose i am
I dose 240ml of afr daily on my current system and have not suffered lowering of my ph.
I switched from redsea 3 part. The 3lb powder containers.

240ml on a 270gal system.

What size system are you using it on that your seeing significant ph drop?

On my current build, 1200-1400gal system im planning on using a combination of afr and kalkwaser, i found out afr powder is available in 33lb containers via special order.

Is the drop in ph your experiencing more significant compared to a calcium reactor?

I do not use it and don't think I'd opt to, but, IMO, it is a reasonable choice for some folks.

The pH drop is based on how it works, not my experience.

The actual pH effects that folks see, up or down, with any dosing method depends strongly on how much and how exactly they are dosing it, and how strong aeration is.

 

[Shooter6]

I do not use it and don't think I'd opt to, but, IMO, it is a reasonable choice for some folks.

The pH drop is based on how it works, not my experience.

The actual pH effects that folks see, up or down, with any dosing method depends strongly on how much and how exactly they are dosing it, and how strong aeration is.

I dose 10ml every hr. With no measurable ph drop. That is comparing 3 years of redsea 3 part, to 2.5 years of afr.
I dont believe my system is more highly aerated in comparison to most others. Im about average.
Are people seeing this drop by manual dosing a large amount only once a day?
Im going to ask the tm U.S. rep his opinion on this as nobody else ive spoken with who use afr have had this come up.

 

[Randy Holmes-Farley Verified Community Expert]

I dose 10ml every hr. With no measurable ph drop. That is comparing 3 years of redsea 3 part, to 2.5 years of afr.
I dont believe my system is more highly aerated in comparison to most others. Im about average.
Are people seeing this drop by manual dosing a large amount only once a day?
Im going to ask the tm U.S. rep his opinion on this as nobody else ive spoken with who use afr have had this come up.

lol

Sure, we can have Lou come here. I love to argue chemistry with him. @Lou Ekus

You would not see a pH drop each time you dose since the acid is not produced until the formate is metabolized. You would, on average, have pH lower than if you were not using it.

 

[Shooter6]

lol

Sure, we can have Lou come here. I love to argue chemistry with him. @Lou Ekus

You would not see a pH drop each time you dose since the acid is not produced until the formate is metabolized. You would, on average, have pH lower than if you were not using it.y

lol

Sure, we can have Lou come here. I love to argue chemistry with him. @Lou Ekus

You would not see a pH drop each time you dose since the acid is not produced until the formate is metabolized. You would, on average, have pH lower than if you were not using it.

You didnt absorb what i said. I compared 3 years of dosing redsea 3 part average ph of 8.1 and current 2.5 years of afr dosing and ph 8.1. Coral growth has increased over the past 2.5 years requiring an increase of dosing, which would in your model cause even more lowering of ph?

 

[Randy Holmes-Farley Verified Community Expert]

An alternate way of looking at the pH effect is by rewriting the equation:

2HCO2- + O2 --> 2HCO3-

It is well understood that adding bicarbonate tends to lower pH. It does so at a measured value of about 0.04 pH units for each 1.4 dKH of alkalinity added instantly. That is why alk additives are not usually bicarbonate alone.

In the same test, carbonate boosted pH by 0.34 pH units and hydroxide boosted pH by 0.66 pH units, all when added instantly.

Obviously, if you spread it out, the pH effect is smaller.

 

[Randy Holmes-Farley Verified Community Expert]

You didnt absorb what i said. I compared 3 years of dosing redsea 3 part average ph of 8.1 and current 2.5 years of afr dosing and ph 8.1. Coral growth has increased over the past 2.5 years requiring an increase of dosing, which would in your model cause even more lowering of ph?

Sure I did.

I also have seen many people report kalkwasser gave them no pH rise, but that obviously is not generally true. Others say it had a big effect. That too is not always true. In my tank, the effect was larger when my skimmer was out of action. But the "effect" of the added hydroxide is the same in each of these cases: it tends to raise pH.

It is certainly fine for folks to claim that the pH effect of carbocalcium was not noticeable to them.

It is not correct to claim it has no pH effect in general. That is easily seen from the chemistry, and is exactly the same as bicarbonate additions.

 

[Lou Ekus]

As much as I love to get into it with @Randy Holmes-Farley whenever appropriate, I can't really argue with chemical equations. What I can tell you is that in the many aquarists that I assist with advice, I have only had one instance of someone saying that they saw a very small decrease in pH when they were adding huge amounts of Carbocalcium to a tank. In that case, however, it also looked like there might have been an issue with a calcium reactor's fine tuning as well. And I think we will find that was the actual issue. So while I don't have any argument with the actual chemical equations, I have to say that given the normal suggested dosing regime of the Carbocalcium or All-For-Reef, the actual observable effects on pH have seemed to be so low as to be deemed insignificant. Hence the claim of stable pH.

I also have to agree with Randy-Holmes Farley (ouch!) that this is one of those things that is very system dependent. The amount of pH instability that one might see will certainly depend on many factors of the individual system and pH monitoring methodology. I would venture to say that it would be entirely possible for two different aquarists to have two different opinions about the stability of the pH in a system, depending on who they are, and how they monitor that parameter.

That all being said, it is my opinion that the ultimate result of pH variance from the recommended dose of Carboalcium or All-For-Reef should be extremely small if any, and have very little influence on the system as a whole.

 

[Shooter6]

Sure I did.

I also have seen many people report kalkwasser gave them no pH rise, but that obviously is not generally true. Others say it had a big effect. That too is not always true. In my tank, the effect was larger when my skimmer was out of action. But the "effect" of the added hydroxide is the same in each of these cases: it tends to raise pH.

It is certainly fine for folks to claim that the pH effect of carbocalcium was not noticeable to them.

It is not correct to claim it has no pH effect in general. That is easily seen from the chemistry, and is exactly the same as bicarbonate additions.

You do know carbocalcium and afr use CALCIUM FORMATE?

 

[Randy Holmes-Farley Verified Community Expert]

You do know carbocalcium and afr use CALCIUM FORMATE?

Uh, yes. My equations used formate:

formate = HCO2-

Calcium has no effect on pH

 

[Randy Holmes-Farley Verified Community Expert]

As much as I love to get into it with @Randy Holmes-Farley whenever appropriate, I can't really argue with chemical equations. What I can tell you is that in the many aquarists that I assist with advice, I have only had one instance of someone saying that they saw a very small decrease in pH when they were adding huge amounts of Carbocalcium to a tank. In that case, however, it also looked like there might have been an issue with a calcium reactor's fine tuning as well. And I think we will find that was the actual issue. So while I don't have any argument with the actual chemical equations, I have to say that given the normal suggested dosing regime of the Carbocalcium or All-For-Reef, the actual observable effects on pH have seemed to be so low as to be deemed insignificant. Hence the claim of stable pH.

I also have to agree with Randy-Holmes Farley (ouch!) that this is one of those things that is very system dependent. The amount of pH instability that one might see will certainly depend on many factors of the individual system and pH monitoring methodology. I would venture to say that it would be entirely possible for two different aquarists to have two different opinions about the stability of the pH in a system, depending on who they are, and how they monitor that parameter.

That all being said, it is my opinion that the ultimate result of pH variance from the recommended dose of Carboalcium or All-For-Reef should be extremely small if any, and have very little influence on the system as a whole.

Thanks for chiming in, Lou!

 

[Shooter6]

Seems calcium formate has a ph of between 6.0 and 8.0, no idea where the tm products fall in this range, maybe i should test that. But here is a link.
"Calcium formate BioUltra, >= 99.0 % T | 544-17-2 | Sigma-Aldrich" https://www.sigmaaldrich.com/catalog/product/sigma/21134?lang=en&region=US

 

[Randy Holmes-Farley Verified Community Expert]

Seems calcium formate has a ph of between 6.0 and 8.0, no idea where the tm products fall in this range, maybe i should test that. But here is a link.
"Calcium formate BioUltra, >= 99.0 % T | 544-17-2 | Sigma-Aldrich" https://www.sigmaaldrich.com/catalog/product/sigma/21134?lang=en&region=US

I think you misunderstand what is taking place.

Calcium formate is not what lowers pH. It will have no immediate effect when added to seawater.

It is when the formate is metabolized to provide alkalinity that the pH lowering comes in.

Same is true of calcium acetate 9Salifert All In One), which has a bigger pH lowering later when metabolized.

 

[Shooter6]

I think you misunderstand what is taking place.

Calcium formate is not what lowers pH. It will have no immediate effect when added to seawater.

It is when the formate is metabolized to provide alkalinity that the pH lowering comes in.

Same is true of calcium acetate 9Salifert All In One), which has a bigger pH lowering later when metabolized.

Can you link me to a study showing this, or explaining it? So far i have not found any data to show this occurring.