i have little white worms in my saltwater tank

Question
i have little white worms in my saltwater tank and was wondering if they would harm any of my fish. I have no isea where they came from. I have not added any thing new to my aquarium in a long time, but however there is green stuff growing in it that i don't know where it came from either. please help me if you can.  I would also like to know if featherdusters need to eat or if they will survive by themselves.

Answer
feather dusters will survive with the food floating in the water. Green stuff - algae. Check your nitrates, probably high. Little white worms, Not sure. go to about.com, click on hobbies and games, then next page click on saltwater aquariums. Great site, lots of info. Gerry.