is TOO much calcium carbonate in tank ever a concern?

[JasonG3333]

Hi - I was wondering if it is possible to over-buffer a tank with too much pH-raising material (whatever that material may be)? Is it possible to raise the pH to a level that is detrimental to the Opae Ula just by adding too much calcium carbonate? For example, what if a tank had all-aragonite substrate (which alone, seems to buffer the tank perfectly, in my experience), but ALSO had a bunch of large coral pieces in addition to that as part of the landscaping - could that result in "too much" buffering/alkalinizing of the water? If so, what would that pH threshold be - like anything above 9 or something? Or would an abundance of calcium carbonate not become an issue (because the pH wouldn't go but so high no matter how much buffering material is present, or the shrimp are fine with very high pH levels, or whatever)? Thanx...!!!

[KenCotigirl]

The simple answer is no. pH and water chemistry is complicated for me so i will not try to explain it. The aragonite and crushed coral do not begin to dissolve by any real amount till the pH gets to about 7.5. They buffer acids formed in the water by decomposition of organics.