That's why having a good aeration system in the pond is critical. A client had a winterkill in one of his ponds with a windmill aerator (2 weeks of cloundy, foggy, overcast days) while his other ponds that had electric compressor aeration systems did fine.

With this hard winter that we had, I suspect that there will be a LOT of pond owners in the same boat.

FWIW I still have 14" of ice on my pond, and the top 10"-11" of it looks like milk.

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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).