What is this?
 

Just added three new pieces of live rock to my new tank and noticed a few hitchhikers. I noticed a very small black and white striped starfish, and what looks like a coral of some type. If anyone know's what these are it would be greatly appreciated.
https://scontent-a-sea.xx.fbcdn.net/...92458552_n.jpg

I would say that's a Manjo Anemone. It's a pest anemone that if left unchecked will take over your tank and make your hair fall out (from stress).

I would wait for verification from another person and then commence the war.

Why are the Manjo Anemone such a problem?, would it even be a problem in a FOWLR tank?

Aiptasia. Majano's aren't as translucent. They also have clubs at the end of their tentacles :)

They can reach plague proportions.

Yes and no. Depends on what you think of their looks. Also depends on if you get a "creeping death" strain or a "rabbits of doom" strain.

But these are Aiptasia, so you probably want to get rid of them regardless. They look like stringy algae when they get going hard. Not very nice at all.

ID
 

Looks to be aptaisia anemone.

couple of options to get rid of them...
1. Slush mixture of sea salt applied directly onto anemone via baster.
2. Aptaisai X chemical remover.
3. a squirt of boiling water on the site.
4. Peppermint shrimp (hit or miss)
5. Certain fish eat it
6. bergia nudibranch
7. cruise missile

the last one might cause a sandstorm...

+1 for aptasia. Aptasia X works good and doesn't release tons of spores all over ur tank.

get aptasia x it comes with a syringe and a couple of different heads
it is easy to use and will get rid of the 3 i see. you have to sneak up on them or they will scoot into the rock. :biggrin:

slighly quicker way is sufficate it with coral glue or apoxy :)

Personally I'd take the rock out and dig /smash around the aptaisia area completely removing it and any signs of it from the rock. Actually though, if it was me I would not even use the rock, it's a plague that may take years to get a foot hold but if it ever does you'll under stand. I see a few in your picture which means they can and probable are hiding every where in the rock.