Holy cow ALK drop

[Moose]

So I have no idea why but my alk dropped and it's usually around 10, but just checked it and it's at 7.8!!!!!!! Any ideas why this would suddenly happen?? A cans are real upset..

 

[Overlook reef]

Do you have a lot of SPS?

What kind of test kit are you using?

Is it possible that you got a bad reading?

Also, coralline algae consumes a lot of Calcium and alk.

 

[jackd625]

Did you take multiple readings, in case it was a mistake? When did you last read it at 10, and have you done a water change or does since then? Corals may be using it up!

 

[ro_nicu]

it's not catastrophic, I used to drop 4 DKH a day if I didn't dose; coraline algae was the culprit.
it does a lot of harm at the same time so you will have to take measures.
Double check. Keep a track of it and see if it's a regular occurrence, decide how you can address it. Ideal would be a calc reactor but drip dosing or dosing in topoff water will work too.
if you go calc reactor you might still have to dose some alk separately as the alc might be used in greater proportion than calc depending on what uses it.