Nausithoe Jelly? Hydroid?

[BrooklynReef]

Hi. I know this is almost imposible with out a pic (im workin on it), but I believed they were hydroids, now after further reading, and seeing them basically turn into jellyfish, I think they are Nausithoe. Ive had welts on my arms (I now use gloves) I believe were coming from them. Could they have killed my seahorse? Though I'm almost positive it was unrelated, but who knows. I heard they are dangerous to corals. I seem to have them in both my tanks, I think they hitched in on some LR.

How can I get rid of them? Do I even need to?

Thanks so much, everyone here is always so helpful.

 

[KathyC]

Without a pic, we'll simply be guessing
You can do it!!

 

[royalson87]

http://www.starfish.ch/c-invertebrates/hydroids.html