Thanks all,
they are in the ref. so I'm not to worried about scratching the tank.
[quote author=kinetic link=topic=1678.msg15370#msg15370 date=1170320392]
yeah, i think it's one of those small tube worms. they're great for the tank, harmless =)
though sucks when they get on your glass and clog up your overflows.
[/quote]
You must have a lot of them, to clog an overflow. ;D
Those blurs in the picture, next to the worms, are isopods. the big one only measures about a 2mm.