Take a sample of the water in a mason or other clear jar and set it in the house or garage where it won't get moved. If the water clears then something is stirring up the water. It's still too cold for turtles to be moving much.

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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).