I have one snail that has so much growing on it that it no longer looks like a snail. It's covered in a thick mat of red algae, has a vermetid snail growing off to one side and has a long feather of green algae sticking straight up from the middle that makes the whole thing look like some kind of crazy Octoberfest hat. I've been trying to get a shot of him for days but he prefers the back of the tank.
Back to the Vermetids, I have a ton of them as well. I have removed a few of the larger ones because the webs were constantly draped over one of my zoo colonies. Aside from that, I would only worry bout them if their numbers drastically increased. I've noticed that my Skunk shrimp has a favorite Vermatid that he will sometimes sit beside for hours while eating it's web.
Thanks everyone for the good news! Mine tend to stay fairly hidden while the lights are on, but if you sneak up on them at night they are outstreated probably a good 2 inches... the first time I saw it I almost screamed! hahaha
I think the vermetids are kinda cool, but I put some new zoos, and they are always covered with the slimy web. Is that just because they're new, or because they are too close to the vermetids.
I was successful removing a few and unsuccessful with a few others. I just took the a razor and scraped them off the rock. But that's not enough because the shell was on the rock but the worm itself was in the rock so, where I could I dug down into the rock with the point of the razor.
I read that you can poke them (ick) or close off the opening with coral glue or epoxy. None of those options appeals to me. I may move the new zoos across the tank so they aren't slimed any more.
I find the webs hold food which my fish then go eat. Like a holding pen it's funny to watch. But they multiply rapidly and like already said, their webs can irritate corals.
The webs can be a problem with some coral but dont bother others. They can go crazy in your tank and creat a problem so would try to keep the numbers down.