What are these?

I dont have the best camera but these are the best pics I could get. I have some green things growing on the left side of the rock. It seems it grows a flat round leaf on top of eachother.

Then if you look to the right of those I have what appears to be a small feather worm. However when you look at it from another angle it is flat and spreads like a fan when out of the tube.

Any ideas or worries here? Thanks.

Brian

 

They look, to me, like a form of macro algae.

 

Halimeda, a type of macroalgae that is calcareous. Good to have in your tank. Just watch for it going sexual. Going sexual looks like the green is going into little balls and you see the skeleton. Remove immediately when you see this. It will take up all of the oxygen in your tank. I learned this the hard way.

 

Cool, thanks 2in10. I guess just keep an eye on it for it turning white huh? I read that Halimeda requires high calcium and alkalinity levels. Should I get those test kits and supplements soon. Brian