I have had my tank running for almost 2 years. Never done bubble scrubbing before. What are the benefits to this and disadvantages? How often should it be done? Daily every other day or twice a week? I'm trying it tonight. I'm not hooking up an air pump. I'm leaving the stand doors open and a fan running in the room the dt is in. I have an external refugium and I just took off the pvc 90 degree elbow for the emergency drain and that's what's creating the air bubbles. Or should I actually put an air pump in the sump and use the pump?