Carbon Dosing with AFR Questions

[Fish Fan]

I don’t have a strong opinion here. I like vinegar for carbon dosing and nitrate reduction, but I’ve had good success with NP bacto balance so I keep using it. I think I dose less than 1ml per day at this point and it’s a 500ml bottle, so not quite a lifetime supply.

I have just gathered what I need to automate my dosing here, and I have two DIY 1120 mL food grade containers (for AFR and Carbon). If on my humble 25 gallon I need to dose lets say 20 mL of AFR, which would be A LOT even if my tank was mature, a 1.1 L reservoir would last me almost two full months. I would think carbon dosing would be about the same

you might need to change your username

Haha, yes, you got me there! I love fish, that's often been my focus (along with motile inverts, which my wife and I both love), but after many years in and out of the hobby, I am finally dipping my toes into some of the easier stoney corals, and I want to get this right

I really thank you and @Miami Reef for your help here, you guys were just the people I had hoped would reply to my concerns

 

[Fish Fan]

Also, I do apologize for flagrent typos, I am on a MacBook with spelling correction that I am still getting used to

 

[Miami Reef]

Vinegar (acetic acid) releases 2 hydrogen ions (H⁺)

The first one immediately when the acetic acid dissociates in water.


The second one later, when bacteria metabolize the acetate and release CO₂, which forms carbonic acid and dissociates.


Ca(OH)₂ (kalkwasser) provides 2 hydroxide ions (OH⁻):

The first OH⁻ neutralizes the initial H⁺, and the second OH⁻ remains available to neutralize the other H⁺ that forms later from CO₂.

@Randy Holmes-Farley can you double check me please?

 

[Fish Fan]

Vinegar (acetic acid) releases 2 hydrogen ions (H⁺)

The first one immediately when the acetic acid dissociates in water.


The second one later, when bacteria metabolize the acetate and release CO₂, which forms carbonic acid and dissociates.


Ca(OH)₂ (kalkwasser) provides 2 hydroxide ions (OH⁻):

The first OH⁻ neutralizes the initial H⁺, and the second OH⁻ remains available to neutralize the other H⁺ that forms later from CO₂.

@Randy Holmes-Farley can you double check me please?

Thank you again for your reply and help! I was hoping not to bother Doctor RHF with this. I've been taking his advice since the old ReefCentral days, and I'm sure he's got better questions to answer

I follow your reply, but could I ask how are you typing out the sub and super scripts here on the forum, such as Ca(OH)2 <(that 2 should be a subscript)? That would be so very much appreciated

 

[rishma]

Vinegar (acetic acid) releases 2 hydrogen ions (H⁺)

The first one immediately when the acetic acid dissociates in water.


The second one later, when bacteria metabolize the acetate and release CO₂, which forms carbonic acid and dissociates.


Ca(OH)₂ (kalkwasser) provides 2 hydroxide ions (OH⁻):

The first OH⁻ neutralizes the initial H⁺, and the second OH⁻ remains available to neutralize the other H⁺ that forms later from CO₂.

@Randy Holmes-Farley can you double check me please?

Miami’s pH neutral carbon dosing vinaigrette.

@Randy Holmes-Farley if it’s not too much trouble what’s the alkalinity contribution of this mixture?

 

[Fish Fan]

Thanks again guys, I'm very appreciative of your help here

 

[Kasrift]

I have a 32g Fluval Flex (worst tank footprint ever) that I've run for 3 and a half years. It is heavily stocked with coral and I have used AFR the entire time. I haven't worried about dosing it during lights out, I dose 1.1 ml every hour 24 times a day.

As for carbon dosing, I actually just use Tropic Marin Bio Actif salt, which has their carbon dosing product in it. Rather than worry about dosing daily, I just assume it bumps things when I do a 5g water change weekly.

 

[Miami Reef]

Here’s my rationale:

Vinegar dissociates in water and makes acetic acid and a proton (acid):
CH3COOH > CH3COO + H+

Bacteria releases CO2 after consumption:

This process is a bit complicated to write out…

But the bacteria release a CO2 molecule.

CO2 + H2O ~ H2CO3 ~ HCO3 + H+
(Carbon dioxide reacts with water to form carbonic acid. Carbonic acid dissociates into bicarbonate + H+ (Acid).

The extra OH from calcium hydroxide bonds to that H+ to make water, effectively neutralizing it.

Just to be clear, one Ca(OH)2 contains 2 hydroxide. 1 works prior and the other works after bacterial consumption.


I’m working on a pH article, so that’s how I’ve been learning about this stuff.

Ethanol ends up releasing 2 protons later after consumption. Not split in half like vinegar.


I don’t know if you guys want me to get into ethanol next. Maybe another day? lol

If I made any mistakes, I’m open to being corrected. I’m sure Randy will come soon to fact check me.

 

[Fish Fan]

Miami’s pH neutral carbon dosing vinaigrette.

@Randy Holmes-Farley if it’s not too much trouble what’s the alkalinity contribution of this mixture?

A vinaigrette of vinager, vodka and a sprinkle of Kalk, though it's been a minute since I've worked Garde Manager in my local restaurant lol!

 

[Fish Fan]

I don’t know if you guys want me to get into ethanol next. Maybe another day? lol

Yes friend, please get into the ethanol, I don't see how it could hurt at this point

So, acetic acid is a weak acid, and does kick off a proton in solution in water; I get that so far. Are you saying that the net from the bacteria growing produces enough CO2 that it becomes carbonic acid and thereby lowers pH? If so, how does carbon dosing help if it reduces nitrates (and maybe to a lessor degree phosphates), but it also decreases pH?

I'm sorry in advance, you're speaking to an idiot.... Please type slowly and use small words.....

I am just trying to understand all these bio and chemical processes, and how I can keep them all in range in my tank. The more I know, the more confused I become.

Thanks again everyone for the help!

 

[Miami Reef]

If so, how does carbon dosing help if it reduces nitrates (and maybe to a lessor degree phosphates), but it it decreases pH?

The bacteria consume nitrate (and phosphate) with the vinegar source. They release CO2 as a byproduct.

Did I understand the question correctly?

Yes, all carbon sources used (ethanol, acetic acid, Bacto) reduces pH. If you saturate Ca(OH)2 with vinegar, you can eliminate the pH reducing effects for that.

 

[Fish Fan]

The bacteria consume nitrate (and phosphate) with the vinegar source. They release CO2 as a byproduct.

Did I understand the question correctly?

Yes, all carbon sources used (ethanol, acetic acid, Bacto) reduces pH. If you saturate Ca(OH)2 with vinegar, you can eliminate the pH reducing effects for that.

I guess I'm asking you specifically - because I value your opinion here very much - would you think the benefit of carbon dosing (for feeding corals and for reducing nutrients) outweighs any concerns of lowering pH, which for me is already low? Many here on R2R tell me not to worry about pH, but if I can at least keep it stable, or dare I say bump it a bit, I think that would be worthwhile. I aspire to have a lot of coralline in this tank, I'd like to keep the pH and Alk up for that reason. Your help here would be much appreciated

 

[Fish Fan]

I have a 32g Fluval Flex (worst tank footprint ever) that I've run for 3 and a half years. It is heavily stocked with coral and I have used AFR the entire time. I haven't worried about dosing it during lights out, I dose 1.1 ml every hour 24 times a day.

As for carbon dosing, I actually just use Tropic Marin Bio Actif salt, which has their carbon dosing product in it. Rather than worry about dosing daily, I just assume it bumps things when I do a 5g water change weekly.

I am really sorry, in the mix of things above I only now just saw your reply, but I very much appreciate it!

I am using the AquaForrest "reef" salt now, I had been using AF's "sea" salt more recently. Much like Instant Ocean and others, the AF "reef" mix is supposed to mix to higher levels than their "sea" mix. However, I have been testing my newly mixed saltwater, and it's coming up short for alk, which is why I'm so focused on my dosing All For Reef.

My concern is that I'll be overdosing the Alk and Calc (or underdosing Mag and micros) if I am also dosing Kalkwasser along with AFR.

Thank you very much for your reply and for your help!

 

[Miami Reef]

Many here on R2R tell me not to worry about pH, but if I can at least keep it stable, or dare I say bump it a bit, I think that would be worthwhile.

Correct.

You technically don’t need to raise pH. You also can technically grow coralline very well at your level, too.


But you can always raise your pH. Is it a PITA? Maybe. Would it increase the rate or coralline and stony coral growth? Likely yes.

My upcoming article is all about this topic.

I keep my pH and alk high because I compete in acro-growing contests.

 

[Miami Reef]

Miami’s pH neutral carbon dosing vinaigrette.

@Randy Holmes-Farley if it’s not too much trouble what’s the alkalinity contribution of this mixture?

Just saw this now. The answer is surprisingly more complicated than expected. I asked Randy the same question 2 years ago.

Short answer: it could be a substantial amount.

https://www.reef2reef.com/threads/h...vinegar-add-to-my-tank.1022991/#post-11996894

 

[GARRIGA]

Wouldn’t adding kalk to a tank based on AFR not defeat the purpose of AFR without adding additional trace and magnesium based on reduction of AFR now being added due to calcium and alkalinity provided by kalk?

Plus those few frags might not consume that additional kalk therefore not making it more complex than needed which also defeats the purpose of AFR?

Perhaps slow drip the carbon thereby allowing the effects on pH to naturally equalize throughout the day. Keep it simple. Just like the intention behind AFR.

 

[RoanokeReef]

I like using AFR and Bacto Balance together. You end up dosing so little Bacto Balance and bottle lasts forever. I like that Bacto Balance contains Phosphate and Nitrate so neither bottom out in theory. However, my Nitrate is always 0 but corals have looked great for the past year as I assume they're taking up whatever Nitrate the Bacto Balance is adding. I also dose have started dosing Ammonia for the last couple months but still always get 0 Nitrates but I haven't increased my dosing of that since my tank looks good.

 

[Miami Reef]

Wouldn’t adding kalk to a tank based on AFR not defeat the purpose of AFR without adding additional trace and magnesium based on reduction of AFR now being added due to calcium and alkalinity provided by kalk?

Yes. That’s true. You’d need to separately dose magnesium. Tropic marine sells A & K, so you can easily add those in. Water changes mitigate the need for Mg dosing.

How big is your tank, FishFan?

 

[TheNative192]

To be honest, I have no plans to add fish to this tank, so concerns about oxygen isn't really important for me now, but I am planing a larger tank with fish, so I do want to get a handle on all f this. I'm planning a much larger display tank build, 150 gallons.

Thank you again for your help, I really appreciate it!!!

I know you are looking to feed the corals as well as lower nitrates but I recently added some Media Seachem Denitrate as I had a similar issue (high nitrates, low phosphates) and my Nitrates went from 20-40PPM to around 5-10PPM and have been stable for over a week and my phosphates stayed the same. I think its just high surface area mini pumice rocks for beneficial bacteria to grow but it really works. I was worried it would bottom out my nitrates but I have not had that issue and I still overfeed slightly (not intentionally lol) I do have fish and I know you currently do not but thought I would mention it. I am in a 20 Gallon setup. It does say it stabilizes at 5PPM nitrates but thought I would mention that as my nitrates were going from 5 to 10 to 20 to 40 all within a couple of days and that fixed my issue. I may look at AFR for dosing once I get my parameters where I want them, right now I just use foundation red sea products.

 

[Fish Fan]

Thank you all for your replies and help, I very much appreciate it!

Correct.

You technically don’t need to raise pH. You also can technically grow coralline very well at your level, too.


But you can always raise your pH. Is it a PITA? Maybe. Would it increase the rate or coralline and stony coral growth? Likely yes.

My upcoming article is all about this topic.

I keep my pH and alk high because I compete in acro-growing contests.

I do not aspire to an Acro dominated tank here, or even clams like I know you keep. I am getting more into some of the stoney corals than I have tried in the past. I know many here at R2R don't worry about low pH, I just thought if it was easy enough to bring it up a bit, then why not, right?

Wouldn’t adding kalk to a tank based on AFR not defeat the purpose of AFR without adding additional trace and magnesium based on reduction of AFR now being added due to calcium and alkalinity provided by kalk?

Plus those few frags might not consume that additional kalk therefore not making it more complex than needed which also defeats the purpose of AFR?

Perhaps slow drip the carbon thereby allowing the effects on pH to naturally equalize throughout the day. Keep it simple. Just like the intention behind AFR.

Yes, for sure adding Kalkwasser will bump my pH, but also add alk and calc, and nothing else, potentially causing an imbalance with the AFR product. That's exactly the dance I'm hoping to do here, if possible

Yes. That’s true. You’d need to separately dose magnesium. Tropic marine sells A & K, so you can easily add those in. Water changes mitigate the need for Mg dosing.

How big is your tank, FishFan?

This is all currently for a humble 25 gallon, and I have zero problems doing regular water changes to hopefully offset any imbalances. However, I have a 150 in the works, so I'm kind of testing the waters with all of this, no pun intended.