When i upgraded from a 55 to a 120 I picked up a cheap $5 trachcan for all of my live rock and so that I could keep most of the water from the tank for the new tank and I added my corals to 2 ice chests with air stones and heaters in each. Monitored the temp and adjusted heaters accordingly.

My corals were in the coolers from Friday night to Sunday night....about 2 and a half days. I also pre-made about 20 gallons of water and added some of it to the trashcan and coolers.

I re-used the sand and added about 120pounds of new live sand. This was all complete late friday night. Saturday I added my rockscape (foam structure) all all of the established live rock right after. I let the tank continue adjusting and added the fish and corals late Sunday evening. I also added a bunch of chaeto to help.

Did not lose one fish or coral.