How long for LR/Corals out of water?

[banditpowdercoat]

I need to move my tank to remove the carpet from under it, and do some plumbing changes in the back. I was planing on moving some fish, the Tangs and easy caught ones to my 45g, then draining 2/3-3/4 water and sump so tank can be moved... Will still be heavy. 150g on stand! But, I was hoping to leave the LR and all in there. But it will be uncovered. How long do I have? before things go bad? Shouldn't be long for the plumbing fixes, but if I don't have to disturb the LR, thats soo much better. Mostly, Mushrooms and Polyps will be uncovered along with the rock