Life in the fuge, ID if you can.

So I two days ago I set up my fuge with nothing in my main tank, waiting for rock to get her... I set it up with the "mud" and maro algae, its all stringy and balls up on its self, o ya and green.
I have let it just go for the past three days and I looked in today and saw this little like 1/4 inch orange polyp looking thing. It is attacked to the mud rocks and has a trunk and a head area with tentacles coming out in a ring. I tried to take a picture but it didn't come out.
I know its not that easy to work out from this little information sorry any help would be nice tho.

 

Keep trying with a pic???

 

Google Aiptasia

 

Yep those are them, should I get rid of them I have heard they are bad, but not sure as to why exactly.

 

Well, they are bad because they can quickly spread and take over a tank. Im not really sure as to how bad they would be considered in a sump/fuge. I would still get rid of it. Order up some Joe's Juice

 

Ok now I have found something else, a few orange slug looking things with a brown stripe, looks like its insides running down the middle any ideas? They are about 1/4 of an inch as well.

 

sounds like flatworms...

 

look anything like this-

 

No it was they didn't spread out to the side like that, and when I was removing them they cureled up in to little balls. Also they could send out spike looking things by the bottom sides of there bodies.

I got ride of all of them so good or bad they are gone now.

 

ohhh, Bristle worms