Originally Posted by
KrazeKajin
My LFS gave me the advice to put a large piece of very porus coral skeleton in my canister filter.
:hilarious
This is like the old question of crushed coral or aragonite sand, both are calcium carbonate (sortof) based. So wouldn't both give you that so called buffer ability. Never mind I'm not going into it.
Crushed Coral is Calcium Carbonate and Magnesium Carbonate but also contains a central structural molecule of Calcium Hydroxy-appetite. The significance of this is that when the crushed coral dissolves, it leaves behind the insoluble Calcium Hydroxy-appetite which is not a contributor to pH stability. You may see it work for a week, but then its gone and the crushed coral sits there and does nothing, nothing at all, and from my understanding your pH would have to be pretty bad for it to truley dissolve for you to be able to benifit from those buffers anyway. Putting fresh crushed coral in gives you the buffer dust from the processing and in the pours, once thats gone its gone.
You might simply want to try the baking soda method, you might also try taking a air pump outside and run the tubing to your skimmer, get the fresh air in there and that could very well take care of your pH.
All in all I'm no expert when it comes to chemistry, but I firmly believe the crushed coral buffering garbage to be just that, garbage. Its just advertising.