dry/base rock is fine, and once seeded will become live rock. You can add base rock, and a few pieces of LR to seed, and cycle your tank that way. I plan on using 50# of base rock to build islands, and then 80# of LR on top. I haven't used their rock, but it looks nice. Also check out reefer rocks. you can have them cherry pick 50#, but it's about $2.50 a pound that way before shipping. The benefit of using dry rock is you can drill it and setup your pillars/islands before adding it to the tank. This way you can take your time setting up your aquascaping base.