Such a thing as an invisible spider in my tank making a web???
 

Ok so I have this piece of live rock, and this hole in it, about the size of an eraser on the back of a pencil.
And it shots out this silk white like web stings, and they attach to near by corals. (and drives me crazy I don’t like the stuff – should I plug the hole?)
Is it good or bad?
Do you guys know what I’m talking about, if not I will post a photo.

Odds are pretty good we're talking about a vermetid snail (stationary). Look for a tubeworm like growth on the rock near to where the web comes from. Try a search on "vermetid" and see how it compares.

They'll spread like mad in a tank (you think "one" of them drives you crazy ... :eek:). You can epoxy over them or try jabbing them with a screwdriver or something... or snip them off with side cutters but be sure to cut as close to the base as possible as they can retreat a fair bit into their tube and if you don't get the snail itself then all you do is give it a haircut (so to speak).

Heres an article from Reefkeeping about vermetid.


http://www.reefkeeping.com/issues/2005-01/rs/index.php

hey you guys are right,
thanks for the article also.
I think I will try and kill them before they spread,