Rising alkalinity after pegging pH at 8.3

[Miami Reef]

I hear you, but I wouldn't say it's impulsive. I've done my planning plus all the other methods you mentioned. I do have precautions in place, as I mentioned 12 Alk was my cutoff. Been reefing for 12 years now, I get bored from time to time, lol.

Ok, maybe not impulsive, but can we go with “risky”?

 

[Nerdist Aquarist]

Ok, maybe not impulsive, but can we go with “risky”?

Definitely! I like crazy roller coasters too. Hmmm, I see a pattern

 

[Shooter6]

I am asking a question,

If I understood the videos o. Youtube about using sodium hydroxide, the raise in alk, is at least partially caused by bound up alk/calcium releasing from the rock sand ect? Any precipitation of dosing that could have collected in the past, releases and increases the alk/cal in the water column. And this will eventually plateau, then decrease to a lower level that is purely the dosing and no leeching?
Does anyone have any insight to this? I believe Chris from aci, and maybe 1-2 others spoke about this occurring?

 

[Dennis Cartier]

I am asking a question,

If I understood the videos o. Youtube about using sodium hydroxide, the raise in alk, is at least partially caused by bound up alk/calcium releasing from the rock sand ect? Any precipitation of dosing that could have collected in the past, releases and increases the alk/cal in the water column. And this will eventually plateau, then decrease to a lower level that is purely the dosing and no leeching?
Does anyone have any insight to this? I believe Chris from aci, and maybe 1-2 others spoke about this occurring?

That does not sound correct. The raise in alkalinity is from the hydroxide and has nothing to do with releasing alk or calcium from the rock and sand. Once something is precipitated to calcium carbonate, it remains precipitated unless the pH drops to a low enough point to dissolve it. Like in a CaRx.

Dennis

 

[Shooter6]

That does not sound correct. The raise in alkalinity is from the hydroxide and has nothing to do with releasing alk or calcium from the rock and sand. Once something is precipitated to calcium carbonate, it remains precipitated unless the pH drops to a low enough point to dissolve it. Like in a CaRx.

Dennis

Yes I know normally the drop in ph is required to trigger the meterials to desolve ( how a calcium reactor functions) I could be wrong but I do believe that was a claim he made and went into a detailed explanation of, without any real science though.
He may be using potassium hydroxide though.
Again I'm not trying to make a claim, presenting a question that may help the op with his dialing in of his parameters is all im trying to do.

 

[Nerdist Aquarist]

I do recall that same video with Chris from ACI. And what he stated about alkalinity rising because of bound up carbonates doesn't make any sense to me either. IMO he's attributing a result with the wrong cause. Then again, I'm no chemistry expert.

 

[Randy Holmes-Farley Verified Community Expert]

My LFS put me onto Seachem Marine buffer. PH peaks at 8.3 and ALK will rise to where you want then figure out the daily amount to does to keep it there.

Get better advice. It's marketing nonsense.

NO additive fixes pH at any specific value, and that product is FAR from the best in terms of raising pH.

 

[Randy Holmes-Farley Verified Community Expert]

I am asking a question,

If I understood the videos o. Youtube about using sodium hydroxide, the raise in alk, is at least partially caused by bound up alk/calcium releasing from the rock sand ect? Any precipitation of dosing that could have collected in the past, releases and increases the alk/cal in the water column. And this will eventually plateau, then decrease to a lower level that is purely the dosing and no leeching?
Does anyone have any insight to this? I believe Chris from aci, and maybe 1-2 others spoke about this occurring?

Not even a glimmer of truth to that.

Such nonsense is why I started reef chemistry forums long ago.

Hydroxide itself is both part of the very definition of alkalinity in seawater, and it is perfectly and exactly measured by the types of total alk kits used by reef hobbyists.

It does not interact with "bound up" alk in rock and sand in any conceivable fashion.

Much of the hydroxide added does combine with bicarbonate in the tank water to form carbonate, but that effect is neutral towards alkalinity. It can also combine with CO2 to form bicarbonate.

Here's a pertinent section from a kalkwasser article of mine, but the principle is the same here:

Hydroxide itself provides alkalinity (both by definition and as measured with an alkalinity test), but corals consume alkalinity as bicarbonate, not hydroxide. Fortunately, when limewater is used in a reef aquarium, it quickly combines with atmospheric and dissolved carbon dioxide and bicarbonate to form bicarbonate and carbonate:

OH- + CO2 --> HCO3-

OH- + HCO3- --> CO3-- + H2O

In an aquarium with an acceptable pH, there is no concern that the alkalinity provided by limewater is any different from any other carbonate alkalinity supplement. The hydroxide immediately disappears into the bicarbonate/carbonate system. In other words, the amount of hydroxide present in aquarium water is really a function of only pH (regardless of what has been added), and at any pH below 9, it is an insignificant factor in alkalinity tests (much less than 0.1 meq/L). Consequently, the fact that alkalinity is initially supplied as hydroxide is not to be viewed as problematic, except as it impacts pH (see below).

 

[Shooter6]

Not even a glimmer of truth to that.

Such nonsense is why I started reef chemistry forums long ago.

Hydroxide itself is both part of the very definition of alkalinity in seawater, and it is perfectly and exactly measured by the types of total alk kits used by reef hobbyists.

It does not interact with "bound up" alk in rock and sand in any conceivable fashion.

Much of the hydroxide added does combine with bicarbonate in the tank water to form carbonate, but that effect is neutral towards alkalinity. It can also combine with CO2 to form bicarbonate.

Here's a pertinent section from a kalkwasser article of mine, but the principle is the same here:

Hydroxide itself provides alkalinity (both by definition and as measured with an alkalinity test), but corals consume alkalinity as bicarbonate, not hydroxide. Fortunately, when limewater is used in a reef aquarium, it quickly combines with atmospheric and dissolved carbon dioxide and bicarbonate to form bicarbonate and carbonate:

OH- + CO2 --> HCO3-

OH- + HCO3- --> CO3-- + H2O

In an aquarium with an acceptable pH, there is no concern that the alkalinity provided by limewater is any different from any other carbonate alkalinity supplement. The hydroxide immediately disappears into the bicarbonate/carbonate system. In other words, the amount of hydroxide present in aquarium water is really a function of only pH (regardless of what has been added), and at any pH below 9, it is an insignificant factor in alkalinity tests (much less than 0.1 meq/L). Consequently, the fact that alkalinity is initially supplied as hydroxide is not to be viewed as problematic, except as it impacts pH (see below).

I did not make the claim, others did.

Now I never once said anything said by others is or is not the truth! I was letting to op know of a possible reason for the issue they are observing, giving them something to research, as a possible cause for the effect. In the end, it's 2 different hydroxide, so I assume that info won't help either way

 

[PeterEde]

Get better advice. It's marketing nonsense.

NO additive fixes pH at any specific value, and that product is FAR from the best in terms of raising pH.

WE have very limited products in Australia.
Only alternative is DIY
So far using Marine buffer my PH has stayed at 8.3 dKh is at 9 dosing 10ml per day

 

[Randy Holmes-Farley Verified Community Expert]

I did not make the claim, others did.

Now I never once said anything said by others is or is not the truth! I was letting to op know of a possible reason for the issue they are observing, giving them something to research, as a possible cause for the effect. In the end, it's 2 different hydroxide, so I assume that info won't help either way

Not sure what the issue is. I didn't claim you were saying it or claiming you said it is true.

I was simply stating for all readers that it is not correct that hydroxide reacts with bound carbonate and should not be thought of as a mechanism.

And again, that is why this forum exists: to exert some chemical rationality to a reef world that isn't always grounded in scientific reality.

 

[Randy Holmes-Farley Verified Community Expert]

WE have very limited products in Australia.
Only alternative is DIY
So far using Marine buffer my PH has stayed at 8.3 dKh is at 9 dosing 10ml per day

It's an OK product (although of unknown purity). It's the claim about it pegging the aquarium at pH 8.3 that is incorrect.

It does not do that. The kernal of truth around that misleading claim is that when added to seawater, it tugs the pH toward 8.3 (whether that is up or down). It's just a mix of mostly bicarbonate and a little carbonate that does that.

But most people do not get as much pH boost as they want from it, and do not get a steady pH 8.3. They would be better off with a pure carbonate supplement, or best yet in terms of pH boost, hydroxide.

 

[PeterEde]

It's an OK product (although of unknown purity). It's the claim about it pegging the aquarium at pH 8.3 that is incorrect.

It does not do that. The kernal of truth around that misleading claim is that when added to seawater, it tugs the pH toward 8.3 (whether that is up or down). It's just a mix of mostly bicarbonate and a little carbonate that does that.

But most people do not get as much pH boost as they want from it, and do not get a steady pH 8.3. They would be better off with a pure carbonate supplement, or best yet in terms of pH boost, hydroxide.

I guess then as my tank matures and corals grow this product wont meet my needs in time

 

[Randy Holmes-Farley Verified Community Expert]

I guess then as my tank matures and corals grow this product wont meet my needs in time

Well, there's no limit to how much you can add, but separate alk and calcium supplements are not the best long term methods.

This has more:

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION

There is no aspect of reef aquarium chemistry more important than calcium and alkalinity. Many of my previous articles have described various aspects of these systems in detail. In reading those articles, aquarists will note one pervasive theme: that maintaining appropriate levels of each are...

www.reefedition.com

 

[Ashish Patel]

Just my 2 cents but why would you want to increase you Alk when your trying to increase PH? At what levels did you maintain before chasing PH? I would try to use another method for increasing PH if Alk is going up too high since only time i've seen real issues come is when my alk went too high.. I am too going to start chasing PH since I've always let it run at whatever it ran at which was 8.0-8.2. I however like my ALK to be a (7.5DKH or 7-8DKH). I find running higher AlK puts me at higher risk of thinks like RTN or STN (just my therory), I feel keeping it closer to natural seawater is always safest bet. Your tank is very nice and whatever your doing is better than 90% of reefers so make small adjustments to one things and cutt back. telling you from experience i have crapped out many time trying to chase something.

 

[PeterEde]

Just my 2 cents but why would you want to increase you Alk when your trying to increase PH? At what levels did you maintain before chasing PH? I would try to use another method for increasing PH if Alk is going up too high since only time i've seen real issues come is when my alk went too high.. I am too going to start chasing PH since I've always let it run at whatever it ran at which was 8.0-8.2. I however like my ALK to be a (7.5DKH or 7-8DKH). I find running higher AlK puts me at higher risk of thinks like RTN or STN (just my therory), I feel keeping it closer to natural seawater is always safest bet. Your tank is very nice and whatever your doing is better than 90% of reefers so make small adjustments to one things and cutt back. telling you from experience i have crapped out many time trying to chase something.

My PH is high 7 if I leave it alone. My ALK was similar. I want to maintain PH 8 and ALK 9-10? Is this unnecessary?
I only have LPS for now

 

[arking_mark]

My PH is high 7 if I leave it alone. My ALK was similar. I want to maintain PH 8 and ALK 9-10? Is this unnecessary?
I only have LPS for now

Many reefers are successful with pH above 7.8 and at all different levels of Alk.

 

[PeterEde]

Many reefers are successful with pH above 7.8 and at all different levels of Alk.

"A decline of 0.1 from pre-industrial times has already been recorded in the pH of the ocean's surface, taking it to 8.1. This corresponds to a 26 per cent increase in acidity. Reef development is thought to cease at pH 7.8"

Australian government study on the GBR. But who knows how factual this study was.

 

[Randy Holmes-Farley Verified Community Expert]

"A decline of 0.1 from pre-industrial times has already been recorded in the pH of the ocean's surface, taking it to 8.1. This corresponds to a 26 per cent increase in acidity. Reef development is thought to cease at pH 7.8"

Australian government study on the GBR. But who knows how factual this study was.

The pH 7.8 is what I consider the "normal" lower limit of OK for a reef, not just because there are many fine reef tanks at pH 7.8 and above, but because as you get below this pH, coral skeletons can slowly dissolve.

This has more:

pH and the Reef Aquarium - REEFEDITION

by Randy Holmes-Farley For many aquarists, pH is not something that they have much experience with aside from their aquarium. For many, pH is almost a black box measurement: something to be considered, but whose physical meaning makes little sense to them. This article will Read more here...

www.reefedition.com

 

[arking_mark]

"A decline of 0.1 from pre-industrial times has already been recorded in the pH of the ocean's surface, taking it to 8.1. This corresponds to a 26 per cent increase in acidity. Reef development is thought to cease at pH 7.8"

Australian government study on the GBR. But who knows how factual this study was.

Most tanks don't regulate pH and in-home CO2 levels will often vary regularly between 400 to 1000ppm CO2. With typical Alk this will fluctuate pH between 7.9 and 8.3 with photosynthesis and other things boosting it a little higher depending on your setup. Many of these tanks are beautiful and have no problem with coral.