Right now on our local news there is a story on backyard pool algae. According to the reporter; pool companies are selling more chemicals this summer than most summers due to the heat and humidity. Advice from the pool specialists they are interviewing:

Test water often.
Spend 15 minutes a day doing pool maintenance.
Stay ahead of the algae instead of trying to get rid of it later. (so far so good)
shock weekly (not necessarily correct)

and of course...

call your local pool company if you need help with pool service to find out what chemicals you need to combat algae. (okay it wasn't too bad a story up until that point)