Algae ID? Never seen this before

[Dolphins18]

Can anyone ID this algae growing on the back glass? I have had this LR for +/- 20 years or so. All the visible areas of the rock are covered in thick coralline so this stuff is only growing on the glass. It has no root structure, but seems to grow from a singular base. Cant tell if the tips are calcified or not.
Any help would be great, thanks!

The 2 bush like growths on the back glass are what I am looking to ID.

 

[vetteguy53081]

Looks like a form of bryopsis
Using an edge of credit card, scrape into a net
Add 1.5ml of hydrogen peroxide per 10 gallons next 2 weeks at night and reduce white light intensity
Is the tank at or near a window?

 

[Dolphins18]

Looks like a form of bryopsis
Using an edge of credit card, scrape into a net
Add 1.5ml of hydrogen peroxide per 10 gallons next 2 weeks at night and reduce white light intensity
Is the tank at or near a window?

No root structure, seen lots of bryopsis, this is not that. I do not want to kill it, just to know what it is.

 

[ReefDragon420]

Looks like a form of bryopsis
Using an edge of credit card, scrape into a net
Add 1.5ml of hydrogen peroxide per 10 gallons next 2 weeks at night and reduce white light intensity
Is the tank at or near a window?

What does the hydrogen peroxide do to the tank ?

 

[AlgaeBarn]

No root structure, seen lots of bryopsis, this is not that. I do not want to kill it, just to know what it is.

codium maybe?

 

[Dolphins18]

codium maybe?

Possibly! It sort of resembles Codium California. No clue how I ended up with it, I should hopefully be able to ID it for sure in a few weeks as it grows. Its fairly pretty.
It may be Codium Fragile actually. Thanks for the help!