Several years ago I began researching what I could do about an old stripmine pond on my property. I wanted to stock it with fish. There is no sign of any fish in there now. I questioned if the water quality was good enough. Surly if it is, there would already be fish. I live in Ohio. Long story short, after attempting to get help from O.D.N.R., the county extension agency, division of soil and water conservation and on, and on, and on.....these agencies are all worthless when it comes to even getting them to call you back. After 2 years of asking for help and researching everything I could I finely got answers. There are no fish because of winter kill. Very fixable by just adding a bubbler. Second, I got the water tested for free from Fender fish farm in Baltic Ohio. Steve Fender is a wonder, helpful guy that has forgotten more about pond health and raising fish them most people will ever know. He tested the water. Found that it is not only about perfect for fish life, but was very impressed that he found Zooplankton in the water. That is the almost bottom of the food chain for fish. Young fry start out life eating zooplankton. I will be stocking my pond in early spring!