Sounds like a good plan. Just make sure you cover any PEX that is exposed to sunlight. Simple pipe insulation will work PEX will deteriorate if the sun stays on it.

I think your assumption is correct. They all went to the shallows looking for O2.

.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!!