Air stone or Pump to stir water surface during outage?

[Bengals888]

Hi,

What provides more O2 during power outage, having an air stone or using a pump position at top to stir the water surface?

The air stone is in fixed postion while the pump moves waters, more O2?

I am working on a back up system for power outage.

 

[lapin]

While an air stone does move water it will not move as much as let say a power head. If I had the backup power I would chose the pump and point it at the surface. It will require more juice. That's why most use air stones for back up. The gas exchange happens at the surface. All things being equal. The more circulation = more gas exchange. I have a generator that will run both my return pump and a heater.