harmful

Hello! I’ve noticed this brown fuzzy looking thing popping in and out of a hole in my hammer coral skeleton (bottom left)I made sure to dip the coral before adding it to my tank, but I guess whatever it is, wasn’t phased by the dip. Any ideas what this could be? Is it harmless, harmful? Hammer...

Over the past two days I’ve noticed a thin and spotty film on the surface of my RO water. Any idea what this is and will it hurt my livestock? I’ve been removing it just by putting a strip of filter pad while mixing water.