Critters in refugium

[Hoochee]

unsuccessful with Google identifying. The critters are under 1/8”.

 

[EricR]

Swimming jellyfish-looking things are likely some type of hydrozoa but I won't venture a guess at specific type.

In general I think you do NOT want these in your DT.

 

[ISpeakForTheSeas]

Swimming jellyfish-looking things are likely some type of hydrozoa but I won't venture a guess at specific type.

In general I think you do NOT want these in your DT.

+1 to the above. I'd guess Cladonema radiatum if you got it from the Atlantic in the US.

 

[Hoochee]

My first thought was hydroids but couldn't find anything similar; however, Cladonema radiatum might be a winner.