Help with identifying

[hreef19]

Hey can anyone help me identify these on my glass just started. Tanks 2 months old. I just lost all my fish from some out break of disease introduced on a sick fish. Tanks been fallow for 4 days and now I have all of these on my glass?

 

[hreef19]

Here is the photo

 

[moose11]

I’m not an expert so take my theory with a large grain of salt, but after my reading online and image similar to this I believe they *could* be hydroids?

 

[kevgib67]

^ agreed.