i am now one of the lowly idiots that works for petco....they actually have saltwater tanks...loli have been working hard trying to clean up the tanks as they had been pretty neglected in the past....i like algae but they don't and i realize that many people have no idea about the benefits of it...especially in marine tanks..
but anyhow........in some of the tank there is something growing on the glass...they are quite small..about 1/8-1/4" long....kinda white looking..almost like a baby anemone or something...they wipe off pretty easy , but a few minutes later they are right back on the glass....almost like they can swim...lol
no jellyfish...feather dusters we have...don't know about tubeworms...
medusae sounds scary...no idea what bryozoans are..
oh yeah...we also get live rock in..could they have come from that ?
i have only been there a week so i have no idea what was in the tanks before....
was in a friends last night... he has marine and has long white worm looking things poking out of the sand, very thin and hardly noticable unless you really look, he is not sure what they are either, dunno if its ysomething from the live rock