In my FW tanks I've sometimes decided to just redo the whole tank's aquascape by removing all the rocks and then readding them. I have about 52 lbs or so of live rock in my 37g SW tank and I'm getting the itch to rearrange the rocks and possibly add more base rock. How sensitive is the bacteria and other fauna that lives in the rock to the air? Should I have a tub of water that I can place the rock into or is that not necessary? I take it I can leave the fish in the tank as I did with my FW setup. Also, if I were to toss my crushed coral (leftover from my old cichlid tank) and replace it with aragonite sand, would there be any cycle due to bacteria loss or is it like replacing the substrate in a FW tank where the bacteria generally colonizes other surfaces? The tank has been set up for about 5 months, FWIW.