What am I?

[Exqui]

Hey guys,

Finally after months of lurking I've decided to set up my account here ...

Could anyone please help to identify this algae?

Many many thanks in advance!

 

[Exqui]

Just in case, here are also a few pictures from my microscope (40x)

Sorry for the quality but I couldn't find my microscope slides anymore....

 

[Exqui]

Anyone, please?

I cannot find any similar looking algae on the net and I'm really out of options currently.
My first thought was that it's Dictyota but it doesn't have the same look.

Just on a side info, the algae came with the rocks, first it has been minimal on one rock only and I've sadly ignored it (I also had to fight caulerpa on it), but recently it really has spread extremely.

I'm currently trying to get my Nitrates under control, even tho my phosphates are getting eaten up by this algae almost immediately.