Best bet would to get on craigslist and look for dead live rock, Its always on there for about 1 dollar a pound. Then go the local Shop and By a small piece of live rock smash it bits and spread it over your dead rock, Run a Blue acintic and 50/50 light above the tank for 14 hours aday, Also dose your system with Calcium, and test till its around 425 on test (use Salifert ) In about 3 to 4 weeks with skimming you will have the start of real nice rock.