Does anyone have any experience with large pacu living outside in a pond with about 30° weather as in the winter it gets cold here to about 30 degrees for about 6 to 8 weeks and we have never had them outside for winter as the pond is new... should we move them inside or try to heat the pond ???? Or will they survive is the my question.. the fish are about 10 years old at about 30 inches in length and pretty thick.. anyone ???