Also have to be careful and determine whether or not the live rock at the LFS is cured. If it is sea fresh and still has some die off, it can cause an ammonia spike in your tank. That could be bad news for the fish if you add a lot of live rock that the current beneficial bacteria population can't handle due to die off. If in doubt, take a big deep whiff (smell) of the the live rock bin. If it smells clean, then it probably is.