hydriods

[Delphinus]

The third picture in particular (the side profile), there's no doubt those are hydroids. I guess some of the others could be small aiptasia but they don't usually stay small like that for very long and end up being unmistakably anemones (if they were). These look like the same hydroids I had. For what it's worth, they never really bothered anything but they just looked fugly. They started dwindling on their own after I added a potter's angel to my mix. Whether that's coincidence or not I can't say but I did read somewhere that pygmy angels might eat them. I'll see if I can find the link.