I am setting up a reef tank and am almost ready to buy rock. For the most part everyone I've talked to has said that it is best to start out using live rock (harvested from the ocean) instead of using dry base rock(which will become live). They had me pretty much convinced until recently. It seems that the more I read about live rock on this site, the more i find where many people (some w/ many years of saltwater experience) are recommending the use of dry base rock over live rock. This has led to start asking several questions over againg that I thought were had been answered already. I would appreciate it if you guys could elaborate on some of the question below. 1) What are the advantages and disadvantages of using live rock? 2) What are the advantages and disadvantages of using dry rock? 3) Why (or why not) is it worth paying 2 or 3 times more for live rock over dry rock? Especially since dry rock becomes live. If it's worth The usual answers i get to this one often lead to more questions. I have listed some of them below. "Because it's better." This tell's me nothing except that whoever is answering doesn't really know what they are talking about. Why is it better? "So you can watch all the SUPRISES that start to grow". This is tempting. We all like surprises. But only when they're good. I don't want bad surprises. In my mind this is kind of like going Trick or Treating and having the possibility of getting tricks instead of treats. Depending to the tricks (and the treats I guess), it makes you think twice about going trick or treating altogether. This usually leads me back to question 3 and also takes me to question 4. "Don't do it, you don't want to introduce pests and problems into your new tank". From my point of view, this is a pretty strong argument for using dry rock, since i am a big believer in using a little prevention to save a lot pain and frustration down the road. This again takes back to question 3 and on to question 4. "It's faster". I'm not sure I'm convinced here. See question 5. 4) What commonly survives on quality live rock that is recieved fresh and is properly cured? It seems that much of the debate over whether to use live or dry rock is over the "hitch hikers" or "goodies" that come w/ live rock. I know coraline is one of the main things, but that seems easy and cheap to come by. So coraline can't be the main justification. What else is there, and is it easy/inexpensive to purchase these things individually instead of trying to aquire them on the rock? Are most of these creatures good or bad? If bad how hard/expensive is it to rid your tank of these pests? 5) Is one faster than the other? From what I have been able to gather, in both instances you have to allow your tank to through the nitrogen cycle before you can start adding fish (or anything else). This is to allow the good bacteria to establish itself in the tank. Please correct me if I'm wrong, but i have heard that this can take anywhere from 1 to 4 weeks for live rock. Would't this take about the same amount of time. Do you have to add fish more slowly when starting out with dry rock? My thinking behind this one is that since live rock has more organic debri on it to decompose during the nitrogen cycle, there will be more bacteria in the tank to handle the bio load from new fish. Or does the bacteria react fast enough to changes in bio load that the initial population would be an insignificant factor when first adding fish? Either way you still have to go slowly, don't you? I can see how coraline would establish itself faster in the tank faster, since there would be surviving coraline all on all the rocks. Is this what people are talking about when they say it's faster? Please correct me if I'm wrong anywhere, and I apologize for being long winded.