I am by no means an expert on anything pond, but did just install an aeration system several weeks ago (kinda like sleeping at a Holiday Inn). After a lot of reading, researching systems and such, IMO, the cost to adequately aerate a BOW of 140 acres would be ASTRONOMICAL. To provide enough turnover to be able to supply enough O2 to even minimally reduce muck, you would have to have multiple stations running multiple diffusers, then there's the issue of power supply. If you have that kind of cash to throw at it, I'd love to be your new best friend!!

You may be better served to try to reduce some of the vegetation and let natural aeration do it's thing.

You could also look into a circulation system to provide enough current to constantly move your water. That too, would probably be very expensive to get something big enough to move 140 acres of water.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!