Cannot raise alk--suggestions?

[adubson]

About a month ago, one of my acros had an overnight bought of RTN which came as a heavy surprise. Until then, all SPS was growing like weeds and anything I threw in the tank was coloring up great. I immediately tested my Alk and Ca, and the Alk was down to 6 on an API test kit (normally held between 8-9). As that has been the only testable element out of whack, my guess is that that must be the issue. But now I cannot raise the alk back to original levels for the life of me!

For some background, I use kalk and vinegar in my ATO with an aqua lifter pump. I dose MB7 bacteria every other week. I was passively running carbon and phosguard, but I just bought a BRS reactor to run ROX carbon and GFO. I bought seachem reef fusion 2 in order to raise the alk. First I dosed the recommended amount for my 75 gallon, alk would raise 1-2 dkh when measured about 1 hr later, but by the same time next day it would be back to 6. I maintained that dose for a bit with no luck, and I'm now up to the max recommended dose with no difference. I tried a simpler approach to go with straight up baking soda (baked, since my pH was down to 8.0 and could handle it) and it seemed to do even less to change the alk when dosing based on the online reef calculator.

Where could my alk be going? I have only 3 or 4 small sps colonies with a small handful more of sps frags, no out of the ordinary coralline growth, and no out of hand nutrients (nitrates = 0 and phosphates are undetectable).

 

[riv]

Not an expert but test your mag. Might be low.

 

[jrpark22000]

It sounds like your tank is now using more alk than kalk can keep up with. You may need to dose a little 2 part daily to supplement the kalk.

 

[adubson]

I don't currently have a magnesium test kit so I'll get on that asap. Could low mag be pulling down the alk?
[MENTION=1277]jrpark22000[/MENTION] could my tank really be going through 2 dkh/day even with the current supplemental 40 ml of reef fusion 2 (max dose)?

I could definitely up my kalk concentration in the ATO water, I'm currently at about 2 tsp/gal.

 

[Siebo]

With the API test kit you are not getting very accurate reads either. I would buy a better test kit or get a Hanna checker. This way you get a better test result.

 

[ultimatemj]

ALK is weird in that once your tank "feeds on it", the demand grows.

That and GFO can add to the "ALK fade"...

If kalk can't keep up, and your confident in your measurements/tests, I'd stick with the sodium carbonate....it will get you there.

 

[Sawdonkey]

If you've only got a little sps, you've got long time before kalk will be insufficient. Fully saturated limewater will go a long way. When it isn't enough, you can add vinegar to supersaturate it. You probably have years before kalk is insufficient.

Are you sure your adding enough kalk to your topoff?

Randy Holmes Farley wrote a great article called "What your grandmother Never Told You About Pickling Lime." Give it a read. It's a little Deep, but he also lays everything out pretty simply.

 

[Sawdonkey]

Is your ato open-top? Do you have a powerhead in the container? Either of these could degrade the limewater.

 

[jrpark22000]

Just found your build thread.
http://www.chicagoreefs.com/forums/showthread.php/22695-Adubson-s-75-gallon-mixed-reef-build

If you have a similar amount of coral today as in your last photos, kalk should be able to easily keep up with your daily alk needs, depending on the kalk concentration.

 

[Addiction]

I have about the same amount of Alk loving corals as you do and I have also struggled to get my Alk numbers up. I'm using Reef Fusion 1 & 2. My coralline algae has really struggled as well so something is missing. I run 6 ATI bulbs on my 75G so lighting cannot be the issue.

How is your coralline growth?

 

[madjoe]

U check your magnesium i believe it plays a big role in alk levels and keeping em stabile and switch to two part eventually corals and coraline use more then kalk can handle . I used kalk on my reef for years then all of sudden just wasnt enough

 

[adubson]

I've ordered a mag test kit, so in the next day or two I can finally test that and see where it lies. Hopefully it's just a quick fix like that.

I currently use vinegar in my ATO with the kalk, but the kalk is not to super-saturated levels yet so I could still raise it. I don't use a stirrer/powerhead because the ATO reservoir (5 gal bucket) isn't air tight. The airline tubing for the ATO pump sits 1 inch off the bottom of the bucket.

As far as the amount of stony corals I have, I've only had a modest increase in frags since my last build thread update, but I wouldn't think that it's enough to cause an alk shortage all of a sudden. Coralline algae has also been increasing throughout the tank, but it seems to be at a constant rate. I think I'll continue to supplement the alk daily to see if it stabilizes at any point, but I'm getting ready to start a regimen of dosing Randy's recipe 1 for 2 part.

 

[madjoe]

Carbon doseing has been known to drop alk vinegar is carbon dosing i believe

 

[riv]

In my tank my mag dropped n I wasn't testing it since it always was stable. Well all of a sudden it dropped n my alk started dropping also. I had alk swings. I started dosing more but could not keep it stable. I lost a lot of my sps. I finally tested my mag n that's when I realized my mistake. I would test your mag n go from there.

 

[adubson]

So I tested my mag with a salifert test kit and it came out to 1200. Is that low enough to mess up the balance?

 

[fredfish13]

That is low. Most like to run above 1350 or so.

 

[ColaAddict]

Try raising your Magnesium. Calc/alk/mag are all tied up together, and if magnesium is off, calc/alk can get very inconsistent. all must be balanced. those are the most important ingredients that can quickly affect your reef.

 

[adubson]

Okay thanks everyone!

I just did a 30% water change with fresh reef crystals, and my alk is between 8 and 9 now. I made the Ca and Alk components of Randy's recipe 1 and will begin dosing that 2 part. Some seachem magnesium will arrive in the mail tomorrow and I'll try to raise my mag up to about 1400 over the following couple days.

Hopefully things stabilize soon, I lost a fresh Cherry Corals acro frag this week to RTN. Not fun.

 

[Addiction]

Sounds like a good plan. Please keep up updated with the progress. Good luck.

 

[Sawdonkey]

Thanks to this thread, I decided to check my mag tonight, which I never do, and it was 1240. I have never had it read less than 1400, so I stopped checking a long time ago. No wonder I've been having bit of trouble stabilizing my alk!