Mark Martin on Photoperiod Algae Control
Mark Martin is the Director of Marine Ornamental Research at Blue Zoo
I get asked a lot about how to control nuisance algae in a tropical saltwater aquarium. I don't like to suggest that people throw a lot of stuff (products or animals) at their tanks to solve algae problems. Instead, I first suggest that people attempt to get their nuisnace algae under control by shortening the amount of light the tank gets (in addition to other good husbandry like cleaning your filters and performing partial water changes).
Changing your photoperiod to get an algae bloom under control is an easy and effective technique. Simply cut back an hour a day on the time that your white lights are illuminating the tank. Then choose one day a week when the tanm will be exposed to no white light. Throughout this time, you may leave your actinics running on a regular schedule. Within a short period of time, you should start to see significant algae die-off.