ID pls: video of hydroids or ?jellyfish?

[Nano]

thats a very cool video! thumbs up. They do look like some type of hydroid/jelly fish to me, and if I'm not mistaken aren't uncommon in newer set ups and tend to die off, but hopefully some one who knows for sure can confirm or dismiss what I have said.. still though that is a really cool look at them!

[ScubaSteve]

99% sure it's a jellyfish ephyra. Haven't the foggiest as to what species though. The other 1% is a coral planula but most planula are ciliated rater than having a medusa form.