Tiny white free swimming polyp thing.

[Cra-z wolf]

I am draining one of my tanks, almost 3\4 down and notice these little star type things on the glass congregated in the corner closest to the window. i shine a light on them and they release off glass and start swimming. Little white polyps swimming. Phyto also gets them moving.
Any ideas?
The tank itself has no coral or anenome, connected to a system with only a rockflower and some palys in one tank. The sump is a 55 gal settling tank and I've not seen any there, only limited to the 1 tank.

 

[xxoczukxx]

they look like hydroid jellyfish

 

[NeonRabbit221B]

+1 for hydroids.

 

[Cra-z wolf]

Ok. So not harmful.
I am breaking tank down. This tank had fairly low flow. will they survive in higher flow tank?

 

[ReefBridge]

They look like hydroids. Those are not good for your reef tank. They can overpopulate and sting corals and fish.

 

[Cole.mormon]

NOT GOOD