Does calcium ever reach 0 ppm?

[Corey Shelk]

Is this possible? Let’s say tanks go without a water change and only do too offs with RODI water and has LPS in it using calcium to grow. Would they eventually run out of calcium and just stop growing or would they start to die? If they would just stop growing then would they continue growing again after a water change that adds more calcium (and other elements) and then stop again once that has been “used up?”
Or does calcium never reach 0 ppm because it’s a salt water aquarium?
Assume no calcium reactor and no dosing calcium, etc.
Also this is not intended to be a thread debating the pros and cons of a water change, I’m simply trying to get a deeper understanding of calcium and the role it plays in our aquarium and stony coral growth

 

[Timfish]

I don't see how calcium can drop to zero in a marine system as dissolution of substrates and exposed coral skeletons by endoliths would be putting bicarbonates and carbonates back in the water. Bicarbonate and carbonates can certainly drop to levels that will cause corals problems and potentially kill them however.

On a more esoteric level pH can drop to the point a coral polyp can't grow a skeleton and survive and start growing a skeleton when the pH rises back up to an acceptable level. This isn't quite the same thing though as having low calcium carbonate.

 

[Corey Shelk]

I don't see how calcium can drop to zero in a marine system as dissolution of substrates and exposed coral skeletons by endoliths would be putting bicarbonates and carbonates back in the water. Bicarbonate and carbonates can certainly drop to levels that will cause corals problems and potentially kill them however

Ah ok, thank you!! I was just trying to see what the effect would be of adding too many LPS to my nano if I maintained the same WC schedule I currently have