There are red hair algae types. There is also one called red cotton algae. Hard to tell until it grows out more.
That was going to be next guess red cotton algae.
this is what reefcleaners says about it.
Algae under this heading usually appear as a light pink fuzz. Closer examination will show it is made up of many branches with even more branchlets. The plants are very small, lose form out of the water and sway in the current. Each plant forms from a single holdfast.
Callithamnion species and the sporophyte stage of
Asparagopsis taxiformis are usual suspects. The pictured specimen is quite good looking, they usually don't have such an aesthetic appeal, and are a dull red or reddish brown.
Manual Removal: Easy if it hasn't taken hold in places your fingers won't fit. Scrape your thumb on the surface it is attached to, while holding the algae like a pencil as you remove it. This helps you get the small holdfast.
Clean Up Crew members include urchins, sea hares, large turbos, emerald crabs and most hermit crabs.
This algae isn't particularly common, but has the ability to grow rapidly from fragments.