36 hrs or so after putting in fermenter, a gray with tints of green stuff covered the inside glass. We're on day six and it's the same thick layer, hasn't fallen back in. I'm worried that this is bad mold or bacteria instead of kreusen. It isn't sitting on the surface of the liquid at all or anywhere the liquid is. Just in the parts of the glass touching the air inside. Small amounts of it is up in the airlock tube, too. Is this normal? It doesn't smell bad or anything. Still smells like beer.