Update...I got home and filter was still working properly (thank God). Scraped all the algae off the sides of my tank and did a water change (but water is still a little cloudy). All fish seem to be acting okay other than one of the angel's is hiding way up inside rock. My question is: what are the chances of the algae coming back like that again? When I purchased the algae scraper it had a bottle of Algae Destroyer Liquid included. Should I go ahead and put some in the water or just wait? I just don't want that film to cover my tank like that again. It took me over an hour to clean!