[jdieck]

Actually that pump might even be small for a 130 gal tank and the manufacturer recommends piping of 11/2" diameter!
The first question I would make is if you are using the pump pre-filter, if you do remove it, it causes pressure drop in the inlet that makes the pump create cavitation ending up in micro bubbles.
Also insure that you have no leaks in any part of the piping from the pump to the main tank, finally insure that the water level in the pump compartment is as high as possible, higher level will creae postive suction pressure which will also prevent cavitation.
I think having the carbon bags in the baffle compartment may be making the water level too low in the pump's compartment by blocking the water transfer from one compartment to the other.
Finally if the tank is relatively new (less than two months) water tends to have some more surface tension while the sand bed and other areas create bacteria that may process some of the organics, that may create some more bubbles for a while.