It looks it might be "red cotton ball algae" Asparagopsis taxiformis
Here is a picture, it sort of looks like what you have:
Here is another picture of the same algae, it looks closer to yours (this is because this algae can be dark red to light pink):
You should get some Mexican Turbo Snails, they should help clean it up. Also check your phosphates, they are probably out of whack. Here's an article about this algae: Algae Articles . Hope this helps.