To me, losing 4' in a week is excessive, but having ground frozen/thawed, I'm not sure. Time will tell.

How was the pond basin compacted? (equipment used, technique) and what kind of dirt did you have to work with?

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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).