Thanks Cecil,
So what is the difference where the 2 posts above had even water temps from top to bottom and you are able to keep your water at 60 even with diffuser? Your pond is smaller so the diffuser should have an even easier time of mixing the entire water mixture to equilibrium? It must be you replace cold water fast enough to keep it cool.
Bingo!
The pond has a volume of about 100,000 gallons and if I remember right 45 gpm is 64,800 gallons of water every 24 hrs.
