Search the forum for similar threads - there are tons of opinions on this. Most here feel that they are good so long as they don't get too big and they are not fireworms, but opinions vary
Originally Posted by Sxy_kya_06 http:///forum/post/2472997
bristol worms. are they ood or bad?
had em for years...never done anything to make me set the traps.
Ive got a couple 5+ inchers and am sure there are lots of smaller ones. I have never had any issues with them except the occasional bristle stuck in finger when messing with the rocks. I see no reason to remove them from your tank.
they are balmed for killing things 99% of the time they are doing what they do best clean the tank of dead material but people see them eating a fish or snail then they all the culperate but in all actuality they are just cleaning up after the death.
Mike