Cleaning a pond, aeration, and other ideas.

I have a pond about 1 1/2 acres. Pond has been overgrown for about 10 years now. Almost have all vegitation off the surface of the water and chemical should be comming in this week to spray residual on the banks.

My question is does anyone have suggestions on a good areator that would supply 2 membrane diffusers about 150 ft apart.
Something that's not going to break the bank.

Pond averages about 5-9' deep and a 20x20 area around 15-18'deep. Should a couple diffusers be enough with a descent size septic tank air pump? Just trying to keep good oxygen in deeper spots and help slow vegetation growth.

All recommendations are welcome.