What is this stringy stuff growing?

[FreshAquariums]

Hello! I have this stringy stuff growing in two of my aquariums and I can't figure out what it is. Any help would be appreciated! Attached the photo.

 

[Fink]

Hello! I have this stringy stuff growing in two of my aquariums and I can't figure out what it is. Any help would be appreciated! Attached the photo.

Looks like some type of hydroid to me, but there are other folks on here far more knowledgeable than me on hydroid identification.

 

[bushdoc]

As above, usually hydroids will dissapear later when tank is more mature.

 

[FreshAquariums]

Thank you both! Just to double check… not harmless and just do manual removal? Seems to give my Zoas a bit of a hard time.