Alk over 20...what do I do?

[poppin_fresh]

Randy,
I had a low alk problem so I added a little baking soda (couple tablespoons) like your article said and retested. I have a little over 150 gals of water volume, so I assumed that would be a slight adjustment. Instead it raised my alk to about 22 dKH (11.5 meq/l)! My calcium has come down a little, but its still at 500. I haven't gotten a snowstorm yet, its been an hour. Should I just wait it out, or panic now.

Thanks,
Jon

[Randy Holmes-Farley]

22 dKh = 7.9 Meq/L

I'd just wait for it to come down on its own, although I'm not sure how 2 tablespoons could raise it so high (unless it might have been more than 2)

For future additions, this calculator should help:

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

and


Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

[poppin_fresh]

Ok Randy,
The Alk has dropped a little, its now 19 dKH. I checked out the calculator you linked me to, but it said I would have to add over a whole box of baking soda to raise my alk from 6 to 20. I didn't measure exactly, but I know I didn't a more than a couple table spoons, so I'm very confused, but will continue to monitor. Thanks for the help.

[Randy Holmes-Farley]

Sure that wasn't 6 to 20 meq/L on the calculator, which would take a lot more?

[poppin_fresh]

Randy,
The Alk is coming down, its about 16 dKh this morning.

Is it possible that a Phosphate reducing product can suppress alk? I had been running Hagen's Phos-X for a couple months and I have been suffering from low alk (about 6 dKh). I took the bags out of the sump on saturday, but didn't recheck the alk before I added the baking soda on sunday. I assumed that the alk was low like it had been for 2 months.

I am wondering if the Phos-X was messing up the test kit or suppressing the Alk. I might put one of those bags in a cup of new SW and see what happens.

Thanks,
Jon

[Randy Holmes-Farley]

It doesn't mess with the kit. It can lead to somewhat more abiotic precipitation, but it can also lead to faster coral calcification, which uses alkalinity faster. :)

[poppin_fresh]

Hmmm... I am going to be setting up a phosban reactor today, so I'm glad to see it doesn't mess with alk directly.

The one thing that has me baffled is why is my Coraline algea receeding? I thought it might be due to low alk or high phosphates. My new PO4 kit shows zero, which I know can be misleading. I even tested my well water and it read 0 PO4 as well, which kind of surprised me. I did expect to see a little in my well water.

[Randy Holmes-Farley]

How long has the coralline been receeding? Any other changes?

[cwegescheide]

Hi Randy,

Would you also reccomend keeping an eye on the sand bed with alk that high? I had fairly high alk for a week or two or so and my arag-alive sand turned to stone.. I don't know if this was the cause entirely though.

Chris

[poppin_fresh]

i noticed a week ago that the purple coralline was dissapearing and the maroon was turning yellow. The only other change I have made is the addition of 2 T-5 HO's about 3 weeks ago. I was only running 2 NO flouros before that, (which are still on with the T-5's). I ran them diffused for a couple days, none of my softies bleached, so I figured the coralline would be fine.

[poppin_fresh]

I also added some Halimeda to my previouly barren fuge about 2 weeks ago.

[Randy Holmes-Farley]

Would you also reccomend keeping an eye on the sand bed with alk that high? I had fairly high alk for a week or two or so and my arag-alive sand turned to stone.. I don't know if this was the cause entirely though.

Sure, that's worth keeping in mind! :)



It could be the high alkalinity has impacted the coralline, or it might be other issues. It's hard to say.