I've been slowly increasing the run times on my aeration pump. Last night it ran the full summertime measure - midnight to 7:00am.
Dunked the thermometer in at lunchtime today to check the water temps. Had 74.5°F surface temp, 71.1°F at 8.5', and 59.9°F at 10'.
The diffuser is sitting 4' off the bottom in ~15' water. Will be interesting to see how long the thermocline holds up.