Hydroid?

[90addict]

Does anyone know what type of hydroid this is and how bad are they to have in tank? They are really starting to be plentiful on my glass (at least that's where I can see them). Are they good or should I try to eradicate? If so, what eats these guys. Thank you

 

[JNalley]

Those are the harmless hydroids. If your tank is relatively new, they should subside on their own as your tank stabilizes... they typically show up within he first month or two and are gone by the 4th or 5th month... ymmv