We used about 100lbs of live rock from 2 other tanks we combined into this tank.
Then we added 120lbs of lava rock from the local landscaping supply place (at .25$ per pound) and about 30lbs of DIY rock.
Plus 220lbs of sand added to the 40lbs of live sand from the existing tank.
Tank has been running for 9 weeks and the coraline is spreading fast!