I gnerally just put mine right in the tank. I've never had any acclimation problems. Almost all of my corals opened up within a short period of time, some immediately. The only problems I've ever had is acclimating higher light corals from my lfs' tank into mine if they have been in his tank for awhile. Once they had adapted to lower light conditions, it takes them awhile to get used to my tanks lighting, which is much higher than the lfs. It took 2 1/2 weeks for my green cup coral to fully open up. I've got a galaxy that was at the lfs for a month or more and he is still trying to acclimate. Other than that, everything opens up right away.