Looking at your first pics, it appears the size of your aeration boil is sufficient. I would consider relocating it to a more centralized location in the pond tho. Maybe even elevating it off the bottom to try to create a thermocline of deep cooler water.
I've seen that diffuser, but not familiar with its bubble production. You need a lot of tiny bubbles to create adequate lift of deeper water.
Surface of your pond is much cleaner than mine, and I'm running 12 hours at night, and still have a lot of phytoplankton scum on top. I took surface temp readings this morning and will be reducing run time for a later startup to let the surface cool more before it comes on.
Where are you taking your temp readings from? They should be from where your diffuser is currently located.
.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!!
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