It sounds like a great project! You are correct, it looks like a LOT of dirt to move, but it will be worth it. A rocking piston compressor would be what you want to look at for aeration

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).