all hail thr great rhomzilla...RhomZilla said:The bottom line and main purpose with the relations comparing powerheads and using an air pump to use with a bubblewand, is water surface disruption. Both can be used to circulate oxygen/co2 mixtures in the tanks, but a powerhead would also have more advantages depending on what other purpose or set up it would be good for; example: waterflow, using with UGF, or as another method of using a filter.