Ranier, this is in my 10 gallon, not my 37 reef.
The 10 gallon has always had swings of algal blooms. unfortunately this one has lasted a while longer and the caluerpa has not taken off agaion(yet) so the sea Hare I believe mowed down teh alga, but because I went away for 3 weeks on vacation, the poop fueled the algae to grow back.
It happens, plus with the summer heat, the tank hangs around 85 degrees or so........ PERFECT for Hair to proliferate.