Weird invert id?

[KLR]

These things are in random spots even on1 of my acros...they dont harm the coral but im just wondering what in the world are they???????

 

[Azurel]

Hydroids of some sort.....Not sure how to get rid of them though....

 

[KLR]

Soshould i try to get rid of them?

 

[Azurel]

I would if possible.....Some of them can sting and irritate corals.....Not sure as to how you would get rid of them though other then manual removal, but then if the get disturbed they can retract.....Not sure really.

 

[KLR]

ok..well maybe these arent harmful1s as i said there are about 6 of them on my green acro and its polyps stay open

 

[KLR]

From what i just read on google.basically all hydroids are harmful,but i wonder why these arent stinging my acro