Why is my tank consuming so much Alk?

[GARRIGA]

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]

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

 

[GarrettT]

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]

@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]

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]

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]

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]

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]

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]

@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]

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]

Possibly low mag and cal/alk precipitating out?

 

[GarrettT]

Possibly low mag and cal/alk precipitating out?

Mag is 1360. Sorry I should have posted this.

 

[GarrettT]

Current and usual parameters

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

 

[GarrettT]

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]

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.

 

[Reef_prop88]

Maybe you're experiencing some precipitation due to high ph? I'm not an expert on the subject, but the link below might be something to look into.

http://reefkeeping.com/issues/2005-07/rhf/index.php#13

 

[LeBon]

Some folk dont like reef crystals because it has high alk, I think 13 as opposed to a typical 11. Maybe they have the right balance for this situ

 

[LeBon]

Some folk dont like reef crystals because it has high all, I think 13 as opposed to a typical 11. Maybe they have the right balance for this situ

 

[GarrettT]

Precipitation, is that just like calcium and alk that got wasted and formed into a solid. Very scientific, I know..