Overshot Alk Correction.....

TheRealChrisBrown

Reef Shark
M.A.S.C Club Member
ex-officio
#1
I was doing some tank maintenance the other day and discovered that my Alk dosing solution was empty. Did an Alk test with my Hanna checker and it was 7.5 dkh, down from about 8.3 dkh last time I checked it. So I went to one of the reef calculators (the BRS one since I wanted to use the BRS Soda Ash) and found out I needed 16 tsp of Soda Ash to bump it up to 8.5 or 9 range. So I mix it up, and add 1/2 of the solution on Wednesday, and the remaining half on Thursday. Stupid me didn't test between doses, because I am apparently an idiot. So I test this morning (Friday) and Alk is 13.5dkh. So either I mathed wrong, converted wrong, got wrong info, committed a series of unfortunate events, or all of the above. Don't be like me, test between doses when making corrections. This is something I know, I just didn't do!

Tank looks great, everything is out and SPS looks fine. Zoas, palys, and LPS are all normal and happy looking.

My thought was to stop my Alk dosing and let it come back down gradually, probably over the course of a few days to a week. If an Alk of 12 dkh is the high side of "ideal" I'm not that far over at 13.5 dkh. I was hoping for some advice that this is the correct course of action. I want to avoid another drastic swing if possible.

Thoughts?
 

Cherub

Hey you
M.A.S.C Club Member
#2
Wow that's high alk! Just quit dosing for a week test every day and make sure it's going down slowly I think the most you can have it at safely is 11.
 

quackenbush

Clown Fish
M.A.S.C Club Member
#7
It was at 8.15 before and it spiked up with every dose, but would come down pretty quickly. Currently at 8.19.
That's cool. With your alk so far out of whack, I would keep an eye out for some crazy Ca fluctuations. I'm not familiar with the specifics in this scenario, but I wouldn't be surprised if you got some precipitation leading to a Ca crash.
 

jda123

Dolphin
M.A.S.C Club Member
#9
If calcium is not precipitating, then it will be fine. You can change water with lower-alk fresh mix (you will need to use Muratic Acid to lower the alk) or just let it come down on it's own.

Soda Ash (sodium carbonate) should have no real impact on PH. Baking Soda (Sodium Bicarbonate) does have the extra CO2 in there.
 

TheRealChrisBrown

Reef Shark
M.A.S.C Club Member
ex-officio
#10
So a week later, I re-checked everything today. My Alk remained at 13.3 DKH with my Hanna checker. I decided to re-check with an old Salifert test kit I had even though the chemicals were expired. The Salifert read 8.9 DKH. Interestingly, there was a calibration solution in the Salifert kit that was supposed to be 6.5 DKH, when I ran it through the Hanna it read 7.5 DKH. I don't know how much stock I put in any of the Salifert results with an expired kit. My Alk reagent for the Hanna says it expires in Dec. 2017, so getting close.

I use the Apex Dos for my daily Alk dosing, rather that shut it to 0 I reduced my daily dose by 1/2. Kept my Calcium dose the same as it was.

Calcium did drop on Hanna checker from 490 to 377, I don't have a second Calcium test to run (expired or not).

Mag through Red Sea kit was 1380

I'm not seeing any precipitation though, all zoas and LPS are fully open and out like normal. SPS all look normal to me as well, certainly not losing anything. Nems are all out and full as ever.

All of this makes me think I might send a water sample out and see where I am really at. Anybody have any suggestions on a lab? The only one I am aware of up north is the Aqua Medic service, but last I checked it was $40 per sample which is fine if that is the going rate....I thought I'd seen it cheaper out there somewhere.
 
#11
So a week later, I re-checked everything today. My Alk remained at 13.3 DKH with my Hanna checker. I decided to re-check with an old Salifert test kit I had even though the chemicals were expired. The Salifert read 8.9 DKH. Interestingly, there was a calibration solution in the Salifert kit that was supposed to be 6.5 DKH, when I ran it through the Hanna it read 7.5 DKH. I don't know how much stock I put in any of the Salifert results with an expired kit. My Alk reagent for the Hanna says it expires in Dec. 2017, so getting close.

I use the Apex Dos for my daily Alk dosing, rather that shut it to 0 I reduced my daily dose by 1/2. Kept my Calcium dose the same as it was.

Calcium did drop on Hanna checker from 490 to 377, I don't have a second Calcium test to run (expired or not).

Mag through Red Sea kit was 1380

I'm not seeing any precipitation though, all zoas and LPS are fully open and out like normal. SPS all look normal to me as well, certainly not losing anything. Nems are all out and full as ever.

All of this makes me think I might send a water sample out and see where I am really at. Anybody have any suggestions on a lab? The only one I am aware of up north is the Aqua Medic service, but last I checked it was $40 per sample which is fine if that is the going rate....I thought I'd seen it cheaper out there somewhere.
Hanna had a batch of bad alk regent. Gave bad readings. Sounds like you might have some of the bad regent.

Also Stone Aquatics will do ICP analysis if you bring in some tank water for $15 in store.
 

TheRealChrisBrown

Reef Shark
M.A.S.C Club Member
ex-officio
#12
Checked everything again today. Alk down to 10.64 (Hanna), Calcium 428 (Hanna), Mag 1400 (Red Sea). I have a new set of Salifert tests coming soon, but for now at least there is progress on lowering that Alk.

In the tank all is still good, all SPS, LPS, zoas and paly's, nems all look fine. Hopefully back on the road to stability!
 
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