What are these???

[J062682l]

Coralline algae has begun to grow white spots?

. Cool look what I found !!

 

[StevenBell]

What you are experiencing is "die-off" As the growth dies on the rock, it basically rots and what you see "the white film" over the rock is just that, rot. It will go away on its own. If this were a tank with no livestock in it, I wouldn’t worry. But. And there is always a but. If you do have fish in there this white film will drive your ammonia up, a lot. If you want, just take the rock out and see if it smells, don’t worry you will smell it if its die off!