I purchased a 90 gallon reef tank from craigslist a couple weeks ago that was still up and running. It came with some larger gravel substrate that I am not very fond of keeping and would like to switch to some fiji pink live sand. What are the main problems I would be running in too? Tank also has lots of live rock that will stay just may be re-arranged a little. There are still fish one shrimp and ricordea mushrooms in the tank.


