I am not so sure... quoting from the above link at Reef Cleaners
"There are many, many species of Green Hair Algae that have feathery branching, and are not necessarily members of the Bryopsis genus"
Below is a pic of a species of Green Hair Algae I had starting up my RSM 250, it was all over the rock, sand & glass, tank cycled & cuc dispatch of it in no time...
Here is a good pic of one common type of bryopsi
See what others think... your pic look to me much like the green hair algae I had...