I recently took most of my live rock out to rearrange as well as a few of my corals. I have heard that letting corals sit out for an hour or so while being kept moist causes no damage, but a couple of my arcoporas expelled a good deal of their zooxanthellae from the tips of their branches. My question is how long should it take for the zooxanthellae to regrow? One colony is missing about 1" of it at the tips. I also am upgrading my PC lighting to a 400 watt MH system, which i just got. Should i wait untill all the zooxanthellae is regrown to set up the new lights even if I move all the corals to the bottom of the tank?