Help identify please

[kp33]

Can someone tell me what this is on my Xenia, it also gets on my glass and rocks. Hope you can see the thin black strands in the pic. Thanks once identified how do I remove.

 

[kp33]

And is this stufff hair algae, sorry about the pic not the easiest where it’s located

 

[Uncle99]

Some Cyano strings that get caught on the branches?
And some green looks like hair maybe…

 

[kp33]

How do I get rid of?