Snowflakes growing in my tanks.

[ALang]

Not hydroids, but star fishes that came in with your live rock. I had them too, but disappearred after a while...eaten by fish or died. Usually pretty harmless.

[DNoakes]

Okay these things are creeping me out. They just started swimming around the tank like jelly fish. There are thousands of them.

[ScubaSteve]

My guess is that they are jellyfish. Jellyfish start out as polyps similar to what you saw on your glass and then release several offspring from a single polyp. If they are free swimming I woouldn't worry too much about your urchins and starfish. I'd be more concerned about your corals/fish. But since these are babies they won't really pack a huge sting, in fact, some of your fish might eat them depending on what you have. Take a picture! I wanna see, I wanna see!

[Zoaelite]

Originally Posted by ScubaSteve

My guess is that they are jellyfish. Jellyfish start out as polyps similar to what you saw on your glass and then release several offspring from a single polyp. If they are free swimming I woouldn't worry too much about your urchins and starfish. I'd be more concerned about your corals/fish. But since these are babies they won't really pack a huge sting, in fact, some of your fish might eat them depending on what you have. Take a picture! I wanna see, I wanna see!

+1, the life cycle of a jelly fish is really fascinating but they tend to die very easily in captivity so I would love to see some photos!

[DNoakes]

Does anyone know if there is any fish or invert that will eat Jellyfish?

[DNoakes]

I posted an attachment to my original post. It shows one pic of one of the jellyfish I will upload another pic with this message.

[DNoakes]

Here is another pic as an attachment of the Jellyfish in my tank.