So, is this $800 aerator going to run on solar power or conventional wired electricity? What is it going to cost to get electrical power to the site? Once you have the aerator motor, how will you mount it into the tank? At what depth will it operate? Will it just stir up solids and keep them in suspension so that your leach field gets filled and stops up?
Aerobic systems are engineered to make sure the solids stay where they are supposed to be and clean effluent goes to the leach field or sprinkler heads. My aerobic system has a fine filtration system to remove solids and treat the effluent with a tiny bit of chlorine to stop any bacterial activity inside the collection tank.
My point is that if a conventional system could be easily improved as you describe, it would be a common thing. I think it is not an easy thing and you will end up with an expensive mess on your hands that is unmantainable and something else to worry with on a regular basis. If you have been approved for a conventional system, why don't you just put that extra $800 into a superior leach field or larger tanks and have something that will really make a difference?
I know you want the best and I applaud you for that. I just think your premise that you can have a pseudo-aerobic system by simply adding an aerator pump is false. If you can find somebody who has done as you suggest and is happy with the result, I will happily eat my words and be your greatest cheerleader. In the end, I think all of us want to give you the best advice.:thumbsup: