It sounds like you have a turbidity problem. Search for a thread "Alum kicks Clay butt" or something like that. Be prepared for a long read, but you need to resolve the turbidity issue before doing anything else. Aeration won't help.

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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).