As long as you dont go below one full turnover of the pond you can keep cutting back as needed. I'm still getting about three turnovers with 9 hours, so as long as I can run at least 3 hours I'm ok. From now on I'll be cutting back 1 hr at a time as necessary until I reach that mark, then itll be up to the fountain. I'm still holding a 3 degree variance, but the bottom is 82. Got a reprieve yesterday and today with cloudy and rain so it should cool a bit.

With your temps being static top to bottom, I think you have a little bit of wiggle room yet. Just keep watching that variance. When you see the temps start to spread, I think you've reached your limit.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!