Tiny jellyfish swimming in tank

[MohrReefs]

Too small to get a picture but its perfectly round, clear with a center white dot, and just pulsing in my tank. No larger than 1mm or 2mm.

 

[Johniejumbo]

look like this kinda? These are hydroids I believe. Snagged this pic from internet search.

 

[Johniejumbo]

There are better pics. Search hydroids and see if they look like that

 

[MohrReefs]

look like this kinda? These are hydroids I believe. Snagged this pic from internet search.

This one is about that size but circular instead of like a tentacle ball.

 

[Texas Rick]