yep, those be nitro bubbles
like a diatom bloom kinda marks the establishment of aerobic bacteria, nitro bubbles mark the establishment of anaerobics. the bubbles may increase to where it looks like you put a bubble wand in the tank. but the growths will calm down and the bubble will decrease big time in a few. one thing though, untill your anaerobics calm down, blow off your rocks and top of your sandbed. try to not allow any bubbles to get trapped by algae and bacterias like dinos and cyano. tanks coming along nicely by the way
