Here I was bored (or got side tracked) lol
I made a quick video,
The Elite 802 is rated for 20 gallons (like your dual outlet from walmart)
The other single outlet pump a generic 10 gallon pump. (single outlet at walmart)
I know gallon ratings on air pums is kinda a bad number to compare by.
The single outlet pump can power 2 of the SMW filters easy, I have to bleed out more than half the air to make the current decent. Also when its on full blast its LOUD.
The dual outlet airpump can power 10 of these things I'M not kidding! At the end of the video I put an airstone on the other end of the 2nd outluet on the the dual pump, you can see how much air that would be for a little 6 gal tank.
I put the plastic pieces in the tank to attempt to show the current from the filter.
Hope this helps!