We have a 40 gallon reef tank and have been battling with hair algae for the past 4 months. We have been changing the water frequently, have replaced all of the sand with new substrate and bio-active live aragonite reef sand. After thoroughly cleaning the tank, it looks algae free for a couple days, but then it comes back and smothers the whole tank and all of the rocks. Our open brain coral is now covered in algae as well. Any suggestions as to how to get rid of it for good? How can I remove the algae from my open brain without harming it?