Unless you can get a 60 day period where the water stays in the pond (no overflow) I wouldn't use Fluridone. Look into using Clipper and do your best to spray all the duckweed. It is prolific seed wise, and there is probably a pretty good seed bank on the pond bottom waiting to germinate.

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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).