pest identification

2 month old tank, started with live rock. Noticed this small black "tube" looking things protruding from the rock last night. Maybe 1 or 2 other places as well. Is this something to be concerned about (vermatid snail?). It could have been there the whole time, I'm not sure... Feels like...

Anyone know what these are? They are tiny worm like looking things. I have an idea of what they may be but not positive. Found them inside the skeleton of a dead alveopora… removed it from the tank to detach it from the frag plug it’s on. I try to leave behind coral skeletons in my tank hoping...

Coral Only tank, no fish/inverts. Any idea what this little tentacle is? I recorded one of them but I see 2 short ones and 1 slightly longer one. If a pest, any advice on how to remove it?

So I recently have gotten several new corals. One of the Alveoporas I got still hasn’t extended its polyps but still has its bright green color. Part of it looks like about 1/4 of it may have died off. I pulled it out today and use my seachem reef dip on it thinking maybe some type of pest was...