Dark green moss type algae?

[Jpmumaw]

So I have this small spot and just a few more super small spots on my rocks and I can't find a similar picture anywhere online! Sorry for the picture quality but to get a pic had to do it on an angle. It's essentially dark green and I had some on my sand I pulled some out and it was like sludge almost and holding all the sand together. Any help would be great. Like normal all parameters are fine just need to check my phosphates though two weeks ago when I used my last of the testing kit it was fine. Any help would be great like to get rid of whatever it is now before it gets out of hand.

 

[Jpmumaw]

In case there is any doubt as to what I'm referring

 

[Jpmumaw]

No one with any idea as to what this is? It's in more places in my tank now but phosphates are 0 and according to my Hannah checkers my parameters are where they should be.

 

[ReeferMaddness843]

Can't really see, but does it look anything like this?

 

[Jpmumaw]

Looks exactly like that only dark green

 

[ReeferMaddness843]

I never figured out exactly what it was, but believed it to be a form of green Cyano. I used chemi clean EXACTLY as the directions state and it's never shown it's face again.
Before and after:

 

[Jpmumaw]

Thanks appreciate the input ordered it so I'll se what happens kinda wanna catch it before it gets crazy