So they both die before temps get to 45*? Say in a Kansas pond at a depth of 12' would the water be warm enough to sustain life for a tilapia to survive? I have not paid enough attention to see where water temps would be in deeper waters, Oh but a thought just popped into my head(scary sometimes I know)The water at that depth would not support fish without oxygen, could you aerate to keep oxygen at that level, well know I guess you couldn't because then it would cool the water through out the pond lowering the temps to a lethal temp. Seems like I was answering my own questions. does this seem accurate?