Reefscape;2470519; said:The first critter is a bristle worm....and no, they are NOT bad....they are a very beficial part of the cleanup crew in a reef aquarium. The only time they become undesirable are when they get UBER large...like 4 or more inches long...
The second item is just a sponge...a filter feeder, nothing to worry about...
2nd
if you WANT to get rid of them...
a n ylon stocking with some food in it plaved in the tank over night makes a good trap