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.