I'll let TJ chime in here when he gets back from vacation next week, but from my understanding the less organic material that is on the pond bottom, the higher your chances are of having the polymer product work. In other words, seal it sooner than later.

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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).