Wind is only a possible part of D.O. in a pond.

If your pond is 15 feet deep then your diffusers need to be in at least 13 feet. IMO. The entire water column needs to be mixed like Snrub said only reason you would have a fuser in 3 foot of water is to keep a hole in your pond during ice and snow times. Remember warmer water holds like half the amount of D.O. then colder water. So you want to be able to mix the deeper cooler water which will then mix with the warmer water and cool the entire pond down. This is why a lot of folks only run their air at night when it's cooler, because during the day the sun will heat it up man. Plus the sun will also produce D.O. with your plants in the water during the day but at night the plants do not do this they take D.O. from the pond it's a slippery slop this time of year with the hot weather and ponds. Just about as slippery as when it's freezing cold out. Each time takes special management depending on your pond and what's in it and how many fish are in it and weeds and all. Bottom line though is if you can put air in your pond your doing the right thing. If it were me I would put it at 15 feet deep on some kind of crate to keep it up off the bottom a little say 8 to 12 inches. Then do as Snrub says and follow strict start up procedures I am sure you can find them in the air section of this forum it's been talked about like 1 million times!! lol

Good Luck,
RC

The only difference between a rut and a Grave is the depth. So get up get out of that rut and get moving!! Time to work!!