[Myka]

Live rocks are also (usually) easier to maintain than fake rock/coral formations. Long-term, I think live rock looks much better since the fake formations are difficult to keep clean and the cheaper ones (that are still fairly pricey) often lose paint over time. However, if you have to treat fish only tank with medications such as copper, it's easier to do this if the rock is acrylic rather than live rock. There are benefits to both, but personally I'd pick live rock over fake formations any day. You can still treat the tanks with medication if they have live rock - you just can't ever use that rock for a reef tank, EVER.