Hitchhiker/Pest Identification Help

[ReefSoup]

Hey All - Looking for some help in identifying a possible pest in my tank. These things are all over my glass and my zoanthid frag and showed up overnight. Tank is about 3-4 months old and added my first corals about 3 weeks ago. I did dip them before putting them into my tank (unfortunately don't have a QT tank for coral, just fish), but given that I used dry rock and sand, I'm assuming whatever these are came off of one of the coral frags.

Any help on identification, how problematic it is and how to treat is appreciated.

 

[Crabs McJones]

Welcome to Reef2Reef!

Looks like a medusa hydroid. They are fairly common and don't cause an issue. They tend to die out on their own as the tank matures.

 

[Tahoe61]

Hydroid jelly, harmless, frequent critter of newer systems.

 

[ReefSoup]

@Crabs McJones @Tahoe61 Thanks for the welcome and thanks for the quick response. First time ever seeing or hearing of these but glad to hear they're harmless.