Calcium just started climbing...

[special-ops-s2k]

Hello-

I've had my tank setup and running for 7mo and up until 48hrs ago have had pretty much rock solid parameters...

Alk 9.5
Calcium 450
Magnesium 1450

I have a Trident and use controlled dosing of BRS components to maintain these numbers... Because of this they rarely stray much from my setpoints. Two days ago the calcium started to rise and I got an alert that it was over 500... I turned off the calcium portion of the dosing to let the corals and my awc bring it back down over the next few days... I've done this before if for some reason Alk or something else gets a bit high. But after 24hrs of dosing no calcium my numbers had crept up to 530-540! I thought this odd but let it continue to set with no dosing of calcium. Today it's at 580+

I pulled open the sump area and found a large chunk of what I am guessing is precipitated calcium?? I cleaned it all out as best I could and I assume it's this chunk dissolving that was adding calcium even though the dosing was off? I also assume the cleaning of it out of my sump broke more free so it'll probably climb more for awhile before it settles down... Does this sound like I'm on the right track? Why did my calcium precipitate so badly? It is dosed about 3-4in above the water line.. should it be closer? It was also right next to my alk dosing line, so I separated them. I don't think they were dosing at the same time but do you think having them that close might have caused precipitation?

Thanks for any and all help!

 

[Randy Holmes-Farley]

I'd double check the testing on some new salt water as I suspect testing error and not some unseen source of calcium.

I cannot think of any precipitate that will redissolve to raise calcium.