Biggen, where did you come with that? I have never read anything that says the sb will dissolve over time
I should have been more specific. Aragonite sand will dissolve over time. Although I wouldn't see why CC
wouldn't either. That is one of the reason Aragonite sand is used so heavily. When it dissolves, it releases buffering agents, CA
, trace minerals, etc. However, in a normal aquarium, the SB dissolved has no major impact on these minerals.
I am really not sure on the chemistry of how it dissolves. Essential Co2
trapped under the sandbed can lower the pH causing the SB to dissolve over time. This is basically how a Calcium reactor would work if loaded with Aragonite. Be aware, that Aragonite will also dissolve up to a pH in the high 8.0's. It is inevitable that part of the SB would need to be "topped off" with new sand.
Someone may be able to explain that a little better that I could. You could also do a search on "aragonite & dissolve & aquarium" in Google and should come up with something.