If you pump in as Cecil does, running the water thru a stacked column, it adds O2 and removes any harmful gasses at the same time. I think if it was pumping continually, it wouldn't freeze up in the winter, no matter how cold it got out.


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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).