A couple of days after I took this picture, my second sister’s fish pond was covered with thick layers of ice. She never turned her water pump off, and the constant movement of the water blowing to the top surface plus the cold front that we had quickly formed thick layers of ice.
My dad poured warm water on top and my sister broke the sheet of ice with this baseball bat, I think this caused a lot of disturbances to the fish. After they were able to remove all the ice, my dad felt sorry for the fish and added warm water to the pond, not knowing that the change in the water temperature can cause the fish to go into shock, and sure enough one of her white and red Koi fish went belly up.
I visited my dad and sister yesterday and the ice that they removed were still there.
And the remaining fish seem to adjust to the new water well.