I was given about 200lbs of live rock from a guy that had recently broken down his tank. He had it in trash cans filled with saltwater being circulated with power heads in his garage? I'm a little concerned about using it the way it is because if hitchhiker and any other forms of contamination. Do I really have anything to be truly conserned about? Since the water wasn't heated I would think most of the hitchhikers would have died off in the cold but I'm not sure. I've never bought actual live rock before. I've only used Real Reef rock. Do I need to clean it or anything before using it?