Calcium increasing

ReefingBliss · Jun 4, 2019

Ok so this is my first tank at this time I only have a few fish (2 black ice clowns, starry blenny, and an orchard dottyback) and a few snails and hermits. I want to start adding coral I am getting coraline algae growth, I bought a Hanna Alk, and Calcium checker and the Alk has dropped from 7.8-7.2, my Calcium has actually increased from 452 to 541. Any ideas and am I good to add corals.

ProfessorAronnax · Jun 4, 2019

Have you added anything or done anything differently to see a parameter change (different salt mix, new additive)?Wouldn't add coral until things stabilize IMO.

ReefingBliss · Jun 4, 2019

Nothing, tested water Tuesday went out of town came back tested again and that was the number.

stevewright1 · Jun 4, 2019

That is a very large fluctuation over a short period of time
you went out of town last Tuesday, so away for 6 - 7 days (Its Tuesday here now)
it could be an error on the testing - either this latest one or the previous one ? that could account for some fluctuation between the 2 numbers
also is your top off water auto or manual ? I have experienced on my own tank in the past, helpful family member topping up evaporated water using water from my salt water mixing tub , thus salinity and other parameters all increased, but not to the extent yours appear to have done

hopefully someone else may chime in with other possible reasons for the seemingly wide swing

Leadfooted · Jun 4, 2019

When your Calcium goes above 500 it burns up ALK fast! I had the same issue. That’s why your Alk dropped. Not sure what’s causing your calcium to raise. Just be sure to only make small adjustments until you figure it out.

ProfessorAronnax · Jun 4, 2019

Leadfooted said:
When your Calcium goes above 500 it burns up ALK fast! I had the same issue. That’s why your Alk dropped. Not sure what’s causing your calcium to raise. Just be sure to only make small adjustments until you figure it out.

Learned something new today!

BeejReef · Jun 4, 2019

My understanding is that calcium and alkalinity can not increase on their own. Unless you're dosing something or did a water change between tests, it almost has to be a testing issue.
Having said all that, I would have swore that my calcium was near 500 (well above the salt mix recipe) for the first month or two. Now it's stable and predictable. Can't explain it.

Crazeh · Jun 4, 2019

As others have said, unless you are adding anything, calcium shouldn't increase on its own. I have never heard of calcium leaching back out of corals or corraline into the water so don't think that's a mechanism for it to increase.

Sounds like a testing error. Check the expiry date of your kit and double test incase it's your method. Goodluck!