I was under the impression that crushed coral substrates will remain effective for far longer than any aquarium setup will last.
-----------Well, that's a nice thought, but unless every drop of new water entering the tank during water changes is as hard as the existing tank water, the coral will react to buffer and become corroded with time.
the calcium carbonate ions (the main one that does the buffering, but as mentioned there are others) that are being released out of the coral into the water will keeping coming out for years and years.
-----------Possibly for years and years, but it does depend on the hardness of the fresh water added every water change.
this is because an equilibrium situation does not exist with the coral/water because of the fact that water changes are constantly changing it.
-----------Right.
if you never changed your water then yes, equilibrium could be reached where no more ions would be released.
-----------Yep.
but since we change our water, after each water change, it changes the equilbrium and more calcium carbonate would be released..
-----------There you go.
I have never heard of crushed coral substrates needing to be changed because they no longer buffer..
-----------Didn't you just say more calcium carbonate is released every water change? It had to come from somewhere, didn't it?
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