Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
Sounds like bristleworms. You will hear many different theories on them. I find them to be helpful and have never had a problem with them. They eat detritus and help keep your rockwork clean. Other will say they eat fish or corals... If you do a search on RC for "bristleworms" it will yield a million results...lol ;D