The first pic looks like hydroids, also some bubble algae. The second pic looks like a ball anemone, though I’d ask for second opinions on this. In the second pic I also see some vermetid snails and spirorbid worms.
This thread is for the general discussion of the Article Hydroids: a reference to some strategies. Please add to the discussion here. Like many of us, I have had problems on and off over the years with Hydroids. The ones that have always given me the most problems are the common ones that...