Snail and Macro algae?

The first two pictures are of these snails in my tank. They reproduce like crazy and when the bright lights turn off there will be hundreds on the glass. Are they reef safe?




This rock used to be covered with Green Star Polyps, which some how died (weird story), but this is now growing on that rock.


I have not been able to identify either of these two and would like help to make sure they are safe for my reef system.

 

Missing the picture of the snails

 

I've got a similar macro that appeared on my lr.



Someone on another board ID'd mine as Scinaia complanata.