Why is my tank consuming so much Alk?

GARRIGA · Feb 11, 2022

Nitrification is going to also consume alkalinity. I counter that with denitrification. I also have porous coral skeletons as part of my nitrification. As the water acidifies then it should be melting the skeletons. Not corals added yet but my alkalinity constantly goes up and I'm having to use acids to reduce it. Nice problem to have. Poor man's simplistic calcium reactor. Calcium over 500, too. I don't dose either. I'm also not perofrming water changes which would export nitrates and recently shown that nitrates consumed by plants or reduced via denitrification release alkalinity. Good thing we have Randy.

Miami Reef · Feb 11, 2022

What salt mix do you use? How large and how often do you do water changes?

GarrettT · Feb 11, 2022

Miami Reef said:
What salt mix do you use? How large and how often do you do water changes?

IO regular. Generally 10% a week or every other week.

Miami Reef · Feb 11, 2022

@GarrettT @Randy Holmes-Farley

First: I am not experienced in chemistry, but I have been following the forum and Randy for some time. Members, please correct me if I’m wrong:

First: I’m seeing that you are dosing Kalk and an alkalinity supplement (without the calcium) if this is correct, then that is a mistake. Calcium and Alk should be taken in equal ratios in reef tanks. If you are dosing x amount of part alk, you should technically dose the same amount of the calcium part.

But, do not do this yet!

IO salt mixes to about 9dkh in my experience.

I see you use the Hannah checker for your alk testing. I believe there is a testing error happening here. Older reagent bottles will test more and more inaccurately. Sometimes you can have a faulty unit.

Your tank shouldn’t have precipitation issues if you aren’t even dosing calcium except for what’s in kalk.

Your frags cannot consume that much alk IMO.

If I misunderstood anything in your OP, let me know.

Do not make any changes to your system based on this post. Maybe I found a lead on what could be wrong, maybe not. Definitely double check your test kit, I really believe Red Sea alk is more accurate (titration style).

GarrettT · Feb 11, 2022

Miami Reef said:
First: I’m seeing that you are dosing Kalk and an alkalinity supplement (without the calcium) if this is correct, then that is a mistake.

Im dosing Ca too. Just didn’t want people to get confused thinking it was 50ml Alk/ 50ml Ca when I said 100mls. I use MA to lower my dKH to about 8 when doing water changes. Regulator IO is actually closer to 11 dKh, so yea it’s pretty high by itself. I have two Hanna checkers for my Alk. They both verified the amount was correct. I used another regiment too. I test daily, same time. It’s the OCD in me unfortunately.

biecacka · Feb 12, 2022

Can you get your LFS to sample test it? Or do you have another bottle of reagent? I have heard there was a batch running around that was producing inconsistent numbers

corey

MBruun · Feb 13, 2022

Alkalinity is a buffer for PH (Ref: Lou Ekus) so it might be as simple as that your tank stabilize the PH by consuming KH

Lou Ekus from Macna:

GarrettT · Feb 14, 2022

biecacka said:
Can you get your LFS to sample test it? Or do you have another bottle of reagent? I have heard there was a batch running around that was producing inconsistent numbers

corey

I used another bottle of reagent to verify. Still the same result. I'm starting to question to overall potency of the B-ionic that I bought. If it wasn't for the manual dosing of 2 part and verification of Kalk per day, I wouldn't believe it. Unfortunately, my PH swings quite a bit throughout the week. Some days it's 7.9 to 8.2 and others 8.15-8.45. Right now it's on the lower end, so my Kalk alone is keeping up with the consumption (pretty typical after a weekend). During the week, it will rise and I'll have to start dosing the 80-100ml again.

ScottB · Feb 14, 2022

GarrettT said:
I'm starting to question to overall potency of the B-ionic that I bought.

I think you are on to something here. That stuff hardens to heavy crystal when it gets the slightest chill. I buy the 20 Gallon mix buckets and have to heat and run a pump overnight to melt it.

Was that a sealed jug? Some LFS sell jugs that THEY themselves mixed. Mistakes can be made.

50ml for that livestock is unrealistic.

minus9 · Feb 14, 2022

Miami Reef said:
@GarrettT @Randy Holmes-Farley

First: I am not experienced in chemistry, but I have been following the forum and Randy for some time. Members, please correct me if I’m wrong:

First: I’m seeing that you are dosing Kalk and an alkalinity supplement (without the calcium) if this is correct, then that is a mistake. Calcium and Alk should be taken in equal ratios in reef tanks. If you are dosing x amount of part alk, you should technically dose the same amount of the calcium part.

But, do not do this yet!

IO salt mixes to about 9dkh in my experience.

I see you use the Hannah checker for your alk testing. I believe there is a testing error happening here. Older reagent bottles will test more and more inaccurately. Sometimes you can have a faulty unit.

Your tank shouldn’t have precipitation issues if you aren’t even dosing calcium except for what’s in kalk.

Your frags cannot consume that much alk IMO.

If I misunderstood anything in your OP, let me know.

Do not make any changes to your system based on this post. Maybe I found a lead on what could be wrong, maybe not. Definitely double check your test kit, I really believe Red Sea alk is more accurate (titration style).

Calcium and alkalinity are never utilized/consumed in the same ratio. Biological processes will uptake alk, algae growth, buffering, coral uptake, etc. You may start dosing alk and Ca at the same amount, but before long you’ll be dosing more over the other. I don’t think I’ve ever dosed 2 part in equal amounts for very long in any of my tanks. Even dosing all for reef I’m dosing/correcting one over the other.

GarrettT · Feb 15, 2022

minus9 said:
Calcium and alkalinity are never utilized/consumed in the same ratio. Biological processes will uptake alk, algae growth, buffering, coral uptake, etc. You may start dosing alk and Ca at the same amount, but before long you’ll be dosing more over the other. I don’t think I’ve ever dosed 2 part in equal amounts for very long in any of my tanks. Even dosing all for reef I’m dosing/correcting one over the other.

Every tank is different. From my own observation, while the ratio may not be 100%, it's pretty darn close. Close enough, that it would take a rather long time to see much of a difference for most people. I went 2 months without checking Calcium, when using Kalk and the parameters were still balanced.

prcardinal91 · Feb 15, 2022

Possibly low mag and cal/alk precipitating out?

GarrettT · Feb 15, 2022

prcardinal91 said:
Possibly low mag and cal/alk precipitating out?

Mag is 1360. Sorry I should have posted this.

GarrettT · Feb 15, 2022

Current and usual parameters

Alk - 7.8
Ca - 410
Mg - 1360
Po4 - .02-.08
No3 - 2-5ppm

GarrettT · Feb 15, 2022

Just tested to verify my B-Ionic and it checks out. I dosed 50ml of Alk and my levels went from 7.3 to 7.8, which aligns with the chemistry calculator.

http://reef.diesyst.com/chemcalc/chemcalc.html

Anyone know how to verify the potency of Kalk? If the Kalk checks out too, then my tank has to be consuming this much Alkalinity right? So bizarre…

Brian_68 · Feb 15, 2022

Lavey29 said:
Interesting when you have people over which means maybe more C02 in the house. I keep an air purifier running next to my tank so there is always clean air blowing in the room. I believe there is some connection with alk and 02 or C02 but I'd have to research it.

High CO2 drops my ph for sure, not sure how an air purifier would help though since it does not remove CO2. An open window would help.