How do I lower Alkalinity?

[rynosreef]

I had a very similar thing happen. To fix the issue I did several 10% water changes over several days. To the saltwater to be used for the water change, I dropped in enough muriatic acid to bring the ALK down to about 5dKh After aerating this water very well over at least 12-24 hours to raise its pH back up it is safe to use. Just keep track of how much salt and how much muriatic acid you use so it’s easier to repeat consistently for subsequent water changes

It was easy to then plan out how many water changes it would take to get into a safe range. In your case 14dKh x 9 =126. 126 + 5 = 131. 131/10= 13.1 dKH resulting dKH after the water change. Another water change at these values would be 13.1x9=117.9. 117.9 + 5= 122.9. 122.9/10 = 12.29 resulting dKH.

Of course it depends on what dKH you lower it to and if you accurately change 10% etc. But this will get your all down in a safe, controlled way.

 

[Fishurama]

It is the exact and precise effect of a water change.

There obviously are other effects that may make alk decline, which I am not guessing about. Since his alk is already high and staying high, these effects are minor, at best, however.

i think you may misunderstand alkalinity if you apply words like dissipate.



That is just so wrong. How could it not matter? Water change alk at 7 dKH vs 12 dKH? Makes an obvious and huge difference.



Not true.

Vinegar will result in no long term lower of alkalinity. As soon as it is metabolized, the alk returns.

You are guessing about it. How do you know his temperatures both ambient and tank? His flow? How much live rock he has? I think you also may not understand alkalinity is you don't understand is does dissipate.
Correct it doesn't matter what salt you use, no salt unless it's a bad batch will shoot you up to 14 by itself.
White vinegar doesn't lower alk... At this point you are a troll, and i don't know how you became a mod since you seemingly know very little. I sadly can't block you so i will just ignore you from here on out.

 

[Randy Holmes-Farley]

You are guessing about it. How do you know his temperatures both ambient and tank? His flow? How much live rock he has? I think you also may not understand alkalinity is you don't understand is does dissipate.
Correct it doesn't matter what salt you use, no salt unless it's a bad batch will shoot you up to 14 by itself.
White vinegar doesn't lower alk... At this point you are a troll, and i don't know how you became a mod since you seemingly know very little. I sadly can't block you so i will just ignore you from here on out.

This is crazy. You are wrong in every sentence (except that you cannot block me in my own forum).

I am an expert chemist (I can prove it beyond any doubt if you require).

I'm trolling my own expert forum??? lol

I'm not guessing anything at all. I gave the EXACT and instantaneous effect of a water change.

Combining any two aqueous solutions, the final alkalinity is the volume weighted average of the alkalinity of the two solutions, barring any precipitation. I explicitly any not guessing about preciptiation,a lthough it is highlu iunlikely a water change with a lower alkalinity than the tank will induce any new precipitation. It will likely reduce it, but I'm not adding in any such speculation to my exact mathematical calculations.

Temperature, flow, and live rock amounts will have no impact whatsoever on the alkalinity of two seawater solutions mixed together, unless somehow it impacts future precipitation of calcium carbonate.

On vinegar, OF COURSE it has no lasting impact on alkalinity. I can show the exact chemical equations, if needed, but I suspect it will fall on deaf ears.

 

[Rickybobby]

What’s the difference between muriatic acid and vinegar? Does anyone have a straight answer for me. My alk is dangerously high and no matter my salt mix it’s high

 

[rynosreef]

Vinegar is an organic source of carbon. Muriatic acid/hydrochloric acid is inorganic

 

[DaneGer21]

Here’s what I refer to for dosing...

How to Lower Alkalinity with Muriatic Acid

Can someone please point me to the article or calculator on how to accomplish this? Thank You

www.reef2reef.com

 

[rynosreef]

As I understand it, this matters because muriatic acid will not have an effect on other biological processes like bacteria population etc. It is simply a substance with ultra low alk and if properly aerated in new saltwater before adding to your tank will only effect the lowering of the dKH by averaging out the values. Once it’s mixed and aerated it’s no longer active in the solution of saltwater you then use for the water change.

 

[Randy Holmes-Farley]

What’s the difference between muriatic acid and vinegar? Does anyone have a straight answer for me. My alk is dangerously high and no matter my salt mix it’s high

lol

This is the chemistry forum. We always provide straight answers to chemistry questions.

That said, I'm not sure what level you want that answer on.

Adding any acid that is strong enough to release a proton (H+) in seawater will, at least temporarily, deplete alkalinity. This is how that happens. It combines with bicarbonate to form carbon dioxide, which provides no alkalinity

H+ + HCO3- ---> H2CO3 (carbonic acid) ---> CO2 + H2O

Muriatic acid (hydrochloric acid) is plenty strong enough, and the released proton depletes alk as above:

HCl ---> H+ + Cl-
H+ + HCO3- ---> H2CO3 (carbonic acid) ---> CO2 + H2O

Other mineral acids such as sulfuric and phosphoric will, as well as bisulfate (see next post) also have this effect, and will deplete alkalinity permanently, just like muriatic acid..

Organic acids that can be metabolized, such as acetic acid in vinegar, also have this initial effect, depleting alkalinity:

CH3CO2H --> CH3CO2- + H+
H+ + HCO3- ---> H2CO3 (carbonic acid) ---> CO2 + H2O

But the organic anion left over (in this case, acetate) may be metabolized by bacteria. When that happens, the alkalinity (bicarbonate) is returned:

CH3CO2- + 2O2 ---> 2CO2 + OH- + H2O ---> CO2 + HCO3- + H2O

Thus, the addition and metabolism of an organic acid such as vinegar will have no net effect on alkalinity.

 

[Randy Holmes-Farley]

Seachem acid buffer can also be used to deplete alkalinity. It is sodium bisulfate:

NaHSO4 --> Na+ + H+ + SO4--

H+ + HCO3- --> H2CO3 --> H2O + CO2

Note: both that compound and muriatic acid have the same huge pH lowering effect on pH per unit of alk depelted,a nd it should preferabnly be dome in new salt water, or extremely slowly in a well aerated aquarium.

 

[Randy Holmes-Farley]

What’s the difference between muriatic acid and vinegar? Does anyone have a straight answer for me. My alk is dangerously high and no matter my salt mix it’s high

I also showed you how to lower it by water changes, if you prefer. Ignore the noise posted by others about that.

 

[GOPMatt]

Muriatic acid is basically vinegar and salt. This id used to get the zinc out of a penny to make it only copper left over (illegal pease don't do this) put a penny on a tiny pile of table salt... Add vinegar wait a few minutes (prior to placing penny make a good scratch into it on the side exposing the inside) wait few minutes and the zinc in the inside will be dissolved and you'll have a shell of copper. Same outcome of you bought store bought muriatic acid. So when you add vinegar to your tank. In a small way it turns into muriatic acid briefly. Acid is just really low alkalinity. You know the ph scale. If you use salt that's a, lower alk then your current salt it's sort of like adding freshwater to lower specific gravity of saltwater they average out to a lower amount.... Your issue mostly you either have not enough calcium in your Aquarium. Or your salt has a bad batch it your not moving your salt before using. Like rolling the bucket around for 5 minutes or so... And Randy Holmes-Farley is probably has the upmost knowledge on chemistry in this forum but also Aquarium or reef Aquarium chem .. Do you realize how many different different elements from the periodic table are in your Aquarium let alone in what salt you add to it. It's mind boggling what corals and fish and inverts need to survive... If Mr. Holmes-Farley gives you advice and takes the time to type it LISTEN TO IT EVERYONE ELSE DOES and it if not always because remember science is not guessing, it's not a hypotheses when it's already proven....

Happy reefing!!

 

[KyOsIBa515]

Little late to the party...however, no one has asked what kind of water you are using? We are all assuming it is probably RO. However, if you are blending any form of tap water into your mix that can create problems. Which furthermore leads me to my concern with dropping vinegar or acid to help reduce alk and ph. A single drop of acid can drop PH from neutral to 2 in any kind of deionized or RO water. However, it can take 200-300ppm of acid to go from a more neutral to 6 PH in tapwater.
Alkalinity is tricky. Outside of maybe ORP it is our hardest parameter to understand. I have found subtle solutions have helped me before going to a route of acid. As much as lowering my tank temperature and opening a window for fresh air and doing a small water change.

 

[Randy Holmes-Farley]

Muriatic acid is basically vinegar and salt. This id used to get the zinc out of a penny to make it only copper left over (illegal pease don't do this) put a penny on a tiny pile of table salt... Add vinegar wait a few minutes (prior to placing penny make a good scratch into it on the side exposing the inside) wait few minutes and the zinc in the inside will be dissolved and you'll have a shell of copper. Same outcome of you bought store bought muriatic acid. So when you add vinegar to your tank. In a small way it turns into muriatic acid briefly. Acid is just really low alkalinity. You know the ph scale. If you use salt that's a, lower alk then your current salt it's sort of like adding freshwater to lower specific gravity of saltwater they average out to a lower amount.... Your issue mostly you either have not enough calcium in your Aquarium. Or your salt has a bad batch it your not moving your salt before using. Like rolling the bucket around for 5 minutes or so... And Randy Holmes-Farley is probably has the upmost knowledge on chemistry in this forum but also Aquarium or reef Aquarium chem .. Do you realize how many different different elements from the periodic table are in your Aquarium let alone in what salt you add to it. It's mind boggling what corals and fish and inverts need to survive... If Mr. Holmes-Farley gives you advice and takes the time to type it LISTEN TO IT EVERYONE ELSE DOES and it if not always because remember science is not guessing, it's not a hypotheses when it's already proven....

Happy reefing!!

Uh, muriatic acid has neither acetic acid (the acid in vinegar) nor salt in it.

hard to argue with the second half of the paragraph, though. lol

 

[TMB]

@Randy Holmes-Farley , Best thread EVER!! For humor that is! I almost fell out of my chair laughing while reading through this.

I don't know how you have put up with all of us dummies over the years!!
Randy, thank you for all your help - I thought someone needed to say this - you are after all basically the godfather of reef chemistry. And I do remember the time period that you were away, so thanks for being here!

TMB

 

[Randy Holmes-Farley]

@Randy Holmes-Farley , Best thread EVER!! For humor that is! I almost fell out of my chair laughing while reading through this.

I don't know how you have put up with all of us dummies over the years!!
Randy, thank you for all your help - I thought someone needed to say this - you are after all basically the godfather of reef chemistry. And I do remember the time period that you were away, so thanks for being here!

TMB

Good to take a positive outlook these days.

Thanks very much for the comments.