While I was cleaning my glass with a mag float this evening, the vibrations shook the sand bed and released a STREAM OF LARGE BUBBLES. Now I've seen a bubble here and there float up before, but this was significantly more? I'm curious to know why. Some back ground. The tank has been running for a little over a year. The sand bed is 2-3" deep. Recent changes. Started solid carbon dosing with EcoBak pellets 2 weeks ago. Started dosing MicroBacter 7 1 week ago. Thank you for your time and information on this.