ok so I was given some once live rock for my tank about 150lbs of it. It had been sitting in some boxes for about 2 years. When I got the rock I didn't bleach it or really clean in much just rinsed it off with hot water. It still had some carcasses on it of bristle worms which I left to decay in the tank to help out the cycling process. There is still some spots of purple coraline algae on it...My question is are those spots just a dried up shell of the algae? Will that algae come back without being seeded? Never used live rock that has been sitting this long out of water.