How much... With sand??

In my future tank I plan on having at least a 2" live sand bed. It is a 75 gallon tank so from what I have read that would be around 112 pounds of live sand. My question is will I need the normal rate of live rock (I think that would be 70-80 pounds in my tank) with all of the live sand, or can I go with a smaller amount of live rock, say 30-40 pounds??

Thank You
Kloned

 

IMO, I would increase the amount of live sand as oppossed to adding more live rock. The amount of live rock that you are planning sounds appropriate for your sized tank, however, I would try to purchase porous rock, which weighs much less in comparison to other types of rock. This will also lessen the amount of money you plan on spending on rock and your tank will become more full of live rock using the more porous rock. The added features such a sincreased surface area, more living bacteria and inhabitants, due to more nooks and crannies!