If you can provide for some light while you're curing it, you might lose less coralline. Keep water really moving in the tub and change as much as you can manage. The lower (and shorter) your ammonia spike is the better, but if you're talking about 30 lbs freshly harvested rock from the ocean, especially south pacific, in 40 gallons of water you'll have a hellacious ammonia spike, which will probably kill most everything on the rock. Such is way it goes with tonga rock, unfortunately; all those nice colors. Anyhow, maybe you can get a few more tubs and split it up. Don't expect the airstone skimmer to do much, but it will help with O2 content. Keep changing water!