A couple more "things" popped up

[JusMeJim]

This is two different things. The lighter colored ones will move completely into a hole and disappear, and then comes back out. The center appears to be fairly flat.

The darker colored one I can't tell much about it. I'm not sure if the back part of it is in a hole or not. Not sure if it moves or is "growing" where it is.

 

[56longroof]

Aptasia. The darker one may be a lightbulb anenome.

 

[Gumbies R Us]

1st one is aiptasia. I would get on top of getting rid of it before it spreads.