I think I have the same thing in my SW Ohio pond. Here's a couple of pics. I "think" I have about 12 acre feet of water. My pond is 2 acres and I'm guessing about 7' average debth. It's just a foot or two in some places and close to 23' at it's deepest. So is the Aquathol Super K the cheapest way to address this or the Sonar?