I have limpet snails, they do no harm, just harmless cleaners in my tanks. They eat film algea and leftovers! Sorry-I can't tell you if they work on hydroids-I don't have any yet!
winkkle;731739 wrote: Will said snails eat polyps or other corals?
126 reef;731770 wrote: Are hydroids those tiny white things that grow in hi flow areas that look like a cross between a sea squirt and a sponge? They grow like crazy on the inside I'm my skimmer and plumbing