Reef newbie question: Does adding calcium drop Alk? How should I be distributing calcium dosage?

[chousecat]

Hello,

I have a 34 gallon tank and thats been running for nearly 3 months now. I have a lot of softies and LPS so I am taking the extra measures to keep my parameters in check. I measured my calcium and it was 410 yesterday (my Alk is 10.3 at this point) and added enough Red Sea Foundation Calcium to get it to 420 based on today's measurement. I added more supplement to get it to 430, left and came back to my Frogspawn looking a bit more shriveled (all the other LPS look fine). I checked my alk and it dropped to 9.4!

I was reading the manual on the Red Sea Bottle and it said no increments of 20ppm to reduce stress in corals, since I was doing only 10ppm I thought I was in the clear

So does adding calcium drop Alk? How should I be distributing my calcium dosage?

EDIT: I forgot to mention that I did not take an Alk measurement when I measured at 420.

 

[Spare time]

If you have a lot of lps, you could have dropped from 10.3 to 9.4 in a day. Many people drop a point or two a day if they do not dose. As long as your magnesium is fine, you dose calcium and alkalinity at different times, and you pour the calcium in an area of high flow, you shouldn't have any sort of precipitation.

 

[Randy Holmes-Farley Verified Community Expert]

Adding calcium by itself in an appropriate fashion does not alter alkalinity at all.

Alkalinity normally drops in a reef tank, especially if alkalinity is on the higher side like yours.

 

[chousecat]

Thanks for the response guys, I am just wondering why it made my frog spawn shriveled then. Its back to normal but I just found it weird that it the Frogspawn shrunk a bit after adding the Calcium.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the response guys, I am just wondering why it made my frog spawn shriveled then. Its back to normal but I just found it weird that it the Frogspawn shrunk a bit after adding the Calcium.

Likely coincidence unless you added it right by the coral and it encountered a cloud of unmixed in ions.

 

[chousecat]

Likely coincidence unless you added it right by the coral and it encountered a cloud of unmixed in ions.

Thank you Randy that makes a lot of sense, I add the CA at the Powerhead which is right above the Frogspawn