I recently changed up my diffuser placement in the pond. I have 6 diffusers in this 3+ acre pond. I changed things by placing 3 diffusers on stands that sets 21" off bottom. These Kasco diffusers are approx. 10 to 12" tall, so the diffuser head is setting at or around 30" off bottom in 9' of water depths. That leaves 3 diffusers heads setting in 7' and 8' and 11' of water. The 11' section is separated from the rest of the ponds bottom by a road bed or what some might call a ridge with the top of the ridge being in 5 to 6' of water. My goal is to reduce water temps on or near the bottom of the larger section(area) of the pond. I also changed from running air 24/7 to 13/7 running at 9pm to 10 am. Again to reduce the water temps during the heat of the summer. I made these changes after watching Bob Lusk's Facebook program. When he said, God must of designed a thermal cline for a reason. It made sense to me, especially after seeing 87 degree water temps top to bottom last summer. After running the system for a couple of weeks now, I still have no thermal cline but I do have cooler water starting around 6' deep. I am waiting on a new DO and Temp probe, so I can't tell the exact numbers right now but I can tell a difference from last year temps just from swimming or getting in the pond. We shall see how things go, hope I don't kill off my fish through pond turnovers.

I have my diffuser set 24" off the bottom and run it from 11PM until 7AM. I do turn it on 24/7 during the summer when a strong cold front comes through and I'll keep it running until it warms up again and the weather stabilizes. I've seen summer cold fronts disrupt the algea bloom and cause a DO sag, when the water goes from greenish to brown it's time to run the diffuser full-time. Night time aeration is a good idea when it's hot but watch out for cold, rainy, overcast weather and adjust for it. I am currently running 24/7, we had two weeks of hot weather followed by a really strong cold front, I am still waiting for temps to warm up before going back to just running it at night.

Thanks Shorty, I'll keep that in mind if we get any cold front here in E Texas. Not likely here for this time of year but we might receive some rains from tropical depressions or hurricanes coming up from the gulf. And after your remarks I think I will go to 24/7 during any of those type of events.

Somewhat on topic, any thoughts on what effect raised diffusers would have on bacteria activity in a pond with heavy detritus?
I'm in the first summer with aeration of a old farm pond. Wondering if it's more effective to lift from the lowest point in my situation.

I am no expert that is for sure. I would say your diffuser will kick up a lot of sediment and may dirty the water. I ran into that until this year and that was with a new pond. I took until the third running season before mine quit kicking up dirt. An older pond will or may have a lot of sediment that may get disturbed.

I'm in a slow process of putting my aeration system together for my little mutt pond. With a max depth of 12 foot in this 2y/o bowl shaped BOW, my initial thought is to elevate the diffuser off the bottom by means of a platform built from milk crates. The design will have 4 crates tied together for the base, then two more stacked in the center. This comfiguration of crates weighs less than 20# without the diffuser and should be easily lifted for maintainance with a tether line at each corner of the base. It will elevate the diffuser 33" off the bottom, bringing it up to approx 9 feet. With this setup, I dont need a base for the diffuser, as it will be mounted to the top crate. Here's the question....

Will this setup still allow the entire water column to get stirred, or will I still get a thermocline below the diffuser?

In my thinking, water would be pulled up thru the "tower" as the bubbles create lift (with no plate), thus mixing everything, but without actually disturbing the bottom as much. The plan is to run it 12/7/365. Running at night during the hotter months, and daily during the cooler to try to maintain a relatively constant water temp throughout while expanding the usable water in my small BOW.