You don't need the controller. Just set about 2 bubbles per second, using the needle valve and regulator pressure control knob. Then watch how the fish react. If they don't seem distressed, raise the rate to about 3 bubbles per second and again watch the fish, this time for at least a day. If no distress, raise the bubble rate a bit more and repeat until the fish look distressed. Then back down about a half bubble per second or until the fish seem normal again, and leave it set at that.