you can add uncured live rock to the tank which will start your cyle or add base rock and add live rock after the cycle, or add base rock and cured or uncured live rock at the same time. base rock is alot less expensive than live rock and adding a few good pieces of live rock to baserock will eventually seed it and make it live rock. IMO cured live rock seems to make the cycle shorter if you have a large amount of it but you also will experience die off on the live rock during the cycle and will loose some of the beneficial organisms that come on it.