You need to allow your tank to cycle once you get it up with water and live rock. When you are cycling just do a 10% water change to keep the ammonia levels below 1.0 Eventually you will get a brownish algae bloom but that's normal. It should take 10 days to 2 weeks for your tank to successfully cycle. Search for Cycle in forums you will get the gist (actually get some really good insights) The hardest part is the wait! Good luck!