Pond Boss Forums AERATION Should I aerate? New surface aerator turned over my water

I bought a Kasco surface aerator so I could keep the stratification in my pond . I bought the 2400 AF 1/2 hp thinking it would aerate just the surface and placed the floating aerator over the deepest part of the pond. I ran it all day as surface water temps were warmer than the current day time temps thinking I would cool the water down some. I came back later and found all my trout in the shallows and when I checked the water temps 8ft down it was the same at the surface 78 degrees. I called Kasco but they were not much help. I was wondering if anyone else had this problem and was thinking of moving the aerator to the shallow end of the pond hoping it would stop the turn over.
Anyone have any suggestions ?

78F is getting up there if you have rainbows. I have two surface aerators and my water is still stratified, at least I think, because all of the trout are down in 12-13 ft of water this time of year. How deep is the intake for the fountain? I can't imagine this could be the issue but maybe it is pulling cooler water from down deep ans bringing it up? Good luck and hopefully your water doesn't warm up too much more.

There is no intake on the floating aerator. All it is, is a floating disk with a motor and a propeller on the top of the motor. which is slightly below the water ! I have cooler water at the very bottom but I know there is no DO in it to support my trout. I am also at 13ft deep and before I added this aerator I had different temps at different depths from 4 to 6 to 8ft. Now all that water is mixed. What kind of surface aerators are you using ? Are they fountains or what I have. Here is an image of it. https://duckduckgo.com/?t=ffab&q=kasco+2400af+aerator+motor%2Fimpeller&atb=v193-1&iax=images&ia=images&iai=https%3A%2F%2F www.thepondguy.com%2Fimages%2Fproducts%2Fkasco_af_cf%2Fkasco-surface-aerator-2400af-4400-af-without-screen-1000.jpg

I have fountains. They are both 1/2HP. I think the people who know better here should be able to tell you if a aerator like you have can mix the water. All I know is that you don't want mixed water in a trout pond in the summer. That is not likely to end well. I hope you can fix the problem.

I AM NOT an aeration expert. However, I did study water body wave properties due to wind a very long time ago.

I believe you need to move your surface aeration away from the deepest water in your pond. A gentle surface disturbance THAT IS CONTINUOUS can put the water column into motion at surprisingly great depths.

Remember stirring the powdered Koolaid in your glass when you were a kid? Even if you inserted the spoon only half way into the glass, you could easily make a vortex that reached all of the way to the bottom.

I suspect that is what is happening with your pond. You have a small gyre rotating your pond water. As the deep water rotates up onto a shallow bank, it must displace the warm water, and the cool bottom water warms a little bit in that location. The deep cool water in your pond gradually warms as it makes that circuit.

Just my 2 cents worth! Good luck getting your trout back to happy conditions.

Disregard what I said above.

I thought you were circulating the pond with a surface device.

I checked your link, and saw the Kasco's operate by spraying the water into the air.

I guess you could get a little evaporative cooling of the water while it is in the air. I wouldn't think that would be sufficient to set up a convection cell to move your deep cool water out of the bottom of the pond.

However, it doesn't matter what the "theory" says, if your experiment is showing different results (the deep water is warming), then you have to follow your experimental data.

Perhaps you should move the aerator to the shallowest spot in the pond where it will operate, without stirring up sediment from the bottom.

The hypolimnetic zone is hard to mix with proper bottom aeration.. the 2 zones are like oil and water-they don't "want" to mix.
A hard roll-over can mix it but I am very doubtful that surface aeration would be able to break that up. Something else has occurred if your temp profile shows similar temps to 6 or 8'. Have you done an O2 profile?