I always keep reference material on hand in case I need it. One of the books I keep close and I highly recommend to every reefer is "Algae, A Problem Solver Guide, by Julian Sprung". It not only chronicles. but it also gives specific ID for a host of algaes both good and bad. It details the biology of alage and how to combat it and keep it at bay. This is an inexpensive piece of literature that is very easy to read and is only 73 pages long with tons of pictures and recommendations. It's just better to be proactive than reactive when issues arise.
Mucho Reef