ID please?

[Will59031]

Started seeing these appearing only in one corner of my tank any thoughts would be appreciated

 

[SaltyT]

They're hydroids. If your tank is fairly new they should diminish over time.

 

[Will59031]

Thanks that’s what I was thinking just not sure. It’s a newer nano I set up with established rock. Don’t really see them from the host tank but likely due to controlled nutrients.