if that is 30Lbs, then i must have miscalculated my rocks. I must have over 40lbs in my tank.(29G biocube)id say your pretty much on par with 30lbs. i wouldnt add more. also, the 1lb per gallon rule is more stores selling rock. i have a 75 gallon and can tell you i only have 50-60lbs in it with it doing fantastic.
+1Not all live rock is created equally.
My guess is that 20-25 lbs of good Pukani will outperform 50-60 lbs of crappy base rock; easily. Very porous rock that displaces a large volume of water is the goal. It isn't fair to compare very dissimilar rock and pretend they are the same. They are not.
Sheer weight of rock may be all we have to refer to, but it is a poor yardstick.