What's Eating My Alk?

[KBennett]

Hi everyone.

My auto top-off pump died a while ago. I usually top off with kalk, but lately I've just been topping off with rodi. I went a while without testing because I've been busy and lazy lately.

I checked everything a couple weeks ago to find that my alk went down to 1.8!!! I had noticed that my corals had slowed their growth, but I didn't think it would be that bad. The only thing I lost was my new porcelain crab . Calc at the time was 360 and mag was about 1250 I think.
Over the course of a few days I dripped my parameters back up to:
alk 8.0
calc 400
mag 1280

I just checked again today and my alk was back to 2.0!
calc right now is 360 and mag at 1280.

I noticed a lot of growth in the past week, but is there something else that could be sucking up the alk? I wouldn't say I have a lot of coral... I changed my carbon and gfo last week as well.

I use a red sea test kit.

Thanks for your help

 

[EricTMah]

Is it expired?

I've never seen alk that low before!

Sent from my Z30 using Tapatalk 2

 

[KBennett]

I know. But it is repeatable. I guess I'll have to get another test kit to verify.

 

[curiousphil]

The concentration of alk relative to calcium is hugely different. Your calcium may be getting used just as fast, but because it's concentration level is so much higher it's less apparent! The amount of alk in our tanks at any given time is miniscule compared to calcium. Just keep on increasing your dosing amount until alk stays steady it's a good problem to have!! Means things are thriving in your tank. Possibly corraline algae is taking off? Or your corals are starting to bulk up? Either way, make sure you add both calcium and alkalinity supplements in balance.

 

[teebone110]

do you know your mag levels?

 

[KBennett]

do you know your mag levels?

1280.

 

[EricTMah]

You should just bring some water to your LFS and have them test your alk to be sure before you spend money on a new test kit.

Are your tests performed around the same time of day?

 

[KBennett]

I'm an idiot.

I was reading the Meg/L instead of the dKh. I got freaked out when I saw that I barely made it on the values table. It wasn't 2, it was 5.3. Still too low but not insanely low.

Sorry guys.

 

[jroovers]

It's an easy error to make, don't beat yourself up! Better to be in error than have alk in the two dkh range. I agree, your alk is still on the low side.

 

[Jewel]

Balance is the key, if you don't add them to balance each other, the Alk will parcipitate