sprkplug, yes the FA makes O2, but I'll bet that if a study was done (ewest, has one?) you'd find that the majority of DO that is in a pond is "produced" by two things - the interaction between the pond surface and the air, and phytoplankton (i.e. "the bloom").

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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).