The tank, in general, will be very light in the rock dept. Those 2 are ~ 27lbs. When I add another, larger rock, I'll likely have a total of 40-50lbs. which puts me far below the 1lb/gallon "rule of thumb". I'll be stashing some 2.5 year old live rock in my refugium along with some chaeto but it won't be a massive amount. I imagine, when it's all said and done, I might have 60-75lbs. of rock in this system. Obviously, I'll be relying heavily on higher flow and mechanical filtration instead of biological.