I just recently dealt with green bubble algae. I had done in my sump and a small amount on a rock in the display tank. I completely stopped lighting the sump which took care of that and bought two emerald crabs which one immediately ate the gba in the tank. In about three days there were no more signs of it. Haven't seen it for a couple months. hard to tell from your pic, is the algae kind of stringy with bubbles on the strings? Our is it basically matted with bubbles? Bubble algae (dinoflangellates) will be stringy with bubbles that extend into the the water far from the rocks.