Yep they are filter feeders which is great because there cleaning the water for you They probably came as a hitch hiker on the rock you got and you didn't see it and they have grown.Where in the world do they come from? They look like worms.
I guess they eat whatever I put in there, cause they are growin!
It is up to youHope they are eating nitrates! I don't care how hard I try they will never be 0 again and my fish don't seem to care at all. I have a lot of coraline algae too
on the walls should I scrape that off or just leave it alone, kinda unsightly.