This is what I know about volume of the container
CO2(g) + H2O(l) + CaCO3(s) --> Ca2+(aq) + 2HCO3(aq)
If you increased the pressure, which is the same as decreasing the volume, the reaction will shift to the side with fewer moles. In this case to the products side.
If you decrease the pressure, increase the volume, the reaction will shift to the side with a greater number of moles. In this case the reactants. I thought if more CaCO3 was created then there would be more formation of CaCO3??