The first thing to do is check for Phosphate as algae loves it. If you don't have phosphate, check your calcium and magnesium levels. We worked on a tank that had a severe hair algae outbreak. The phosphates and nitrates were both 0. We found that the calcium, alkalinity and magnesium were all really low. The calcium was at 280, magnesium was at 990, and DKH was at 8. We found that once we brought these parameters back up along with a blackout period, the algae disappeared. We call it death by calcium!! We brought the calcium level up to 450, magnesium to 1300, and DKH up to 10. The tank is running great now.


