If its what I think it is its cyano bacteria and its not an algae.
Solutions is to increase flow into the area, decrease feeding, increase water change size and/or frequency.
Theres Red Slime Remover that will remove it within two days however, this is a temp fix and you should take other actions before using it. Its a pain to remove from the water and will make skimmers run wet. I made the mistake and used it when I first started as I rushed and took me 4 20 gallon water changes to remove it.