Later on, little dots of dark mold grew on the paper on the drywall. These are easily removed with bleach.
But there are also white hairy mold growing out of the concrete! If I shine an ultraviolet light on them for a few days they disappear. If I remove the light they grow back. In some area the mold grow so dense it looks like coral reef in air.
It's very strange because firstly, I thought the concrete has dried. Secondly, other than water, what's there for the mold to eat?
I turn the uvc light back on. When the white mold disappear, I plan to clean that concrete area with bleach to see if that would prevent them from growing back when I remove the light. Is there a better solution?
I don't go examine that area very often to avoid unnecessary exposure to mold.