I am just north of Dallas TX.
My pond has a waterfall, flows over a 10ft rock bed stream and into pond. I dont worry about extra Oxygen.
It gets sun in the morning, in shade of house by 2pm.
I also have a drip line from my flowerbed going into the pond, it gets about 5 minutes a day of fresh water. And sprinkler water when we water the lawn. I dont declor this water and it seems to be fine. Early morning watering times.
But it does get really hot here. Not unusual to get a water temp over 90' in the summer.
I was a bit worried the other day when we had a power outage from 3pm-6:30pm, but the fish all seem to be fine!
I also worry about sudden temp drops when we have a Summer Thunderstorms. They can be very COLD water and May have HAIL! I dont care about the hail tearing things up(nothing I can do about that), but the sudden Temp drop from it!!