Algae ID? Is this bryopsis?

[craftycamper]

Im having a pretty annoying and unsightly algae issue in my new tank. This stuff popped up pretty recently but grows really quickly. It went from a tiny bit of fuss to this mess in about a week. I didnt have any livestock outside of corals so when I checked my nitrates and phosphates, they were bottomed out, I assume because of this algae consuming all of it. Im trying to ID it but I cant find similar photos online. It grows on the sand and rock, and sticks pretty tightly. If I want to scrub it off I have to be extremely aggressive about it, it doesnt come off easily. I have been trying to manually remove it but its a massive PITA. As far as nutrient input to the system, I have dosed reef roids once for my few frags but that's about it outside of the initial ammonia dose for cycling.

 

[tbrown]

At first glance it looks like GHA but taking a closer look it does kind of appear fern-like.