tiny white or brown worms

Question
We set up a 14 gallon bio cube using 16 pounds of Fiji live rock as well as 20 pounds of live sand.  We have 2 aquacultured clown fish, 2 white banded coral shrimp, 1 crab-not sure what kind, 12 hermit crabs.  I've been feeding frozen brine shrimp, frozen formula 2, and oraglo pellets.  Just this morning I noticed tiny worms crawling around the tank.  They appear to have white bellies with a darker back.  They're only about a 1/4" long.  Any idea what they are?  Are they detrimental/beneficial to my tank?  Also, what other creatures would you suggest for the tank?  Eventually I'd like to have an anemone for the clowns, possibly some hardy corals, maybe 2 other small fish.  My tank appears to be doing well.  All the levels are currently perfect.  Any suggestions would be greatly appreciated.  Thank you!  -Darcey

Answer
Not sure what the worms are - could be copepods. If they are, get a mandarin fish [dragonette family]. They are exquisite, small, eat copepods, and not terribly expensive. Aquacultured clowns will sometimes not recognize the symbiosis with an anemone. Sounds like a great little setup. Enjoy, Gerry.