Just curious if anyone can identify

[humbletumble]

Had these pop up in my old tank, though more flower like with a small white center. This pic is tank from my current tank, in a corner with lots of light. I'm more than certain they are not harmful, but I am curious if anyone can identify them. They are tiny, with an overall size of a pinky nail or less, and are translucent except for the center and ends.

 

[KrisReef]

I believe that they are a hydroid. Not sure if this one is transient or a problem, many kinds out there and some create long term problems if the overrun a tank. If you had them before and they were not a problem they seem to be around but hopefully they will not explode. I have not had them like Aiptasia and AEFW, the latter is a huge problem, I have had both and would guess your visitor is going to remain safe and perhaps disappear, if I have had hydroids mine went away by themselves so I don’t remember it never saw them become a problem.

 

[humbletumble]

I believe that they are a hydroid. Not sure if this one is transient or a problem, many kinds out there and some create long term problems if the overrun a tank. If you had them before and they were not a problem they seem to be around but hopefully they will not explode. I have not had them like Aiptasia and AEFW, the latter is a huge problem, I have had both and would guess your visitor is going to remain safe and perhaps disappear, if I have had hydroids mine went away by themselves so I don’t remember it never saw them become a problem.

Great info!
That seems like what these are.
Is it a problem to just wipe them off and let the filter take care of them?
Or should I just leave them be?
They were never a problem before, so that's a plus.

Appreciate the info!