James, keep in mind that I'm an amateur from a totally different part of the country. Two things strike me from your description of your lake. The first is your feeding of your fish. If they're taking pellets, they might not want any other food. Are you feeding now? Are the fish taking the pellets.
The second thing I notice is the brown water in the summer. Is this really zooplanton? Might this be tannen instead? I spent one winter at Cedar Key and was able to electrofish with a Florida fisheries crew out of Lake City. We surveyed a large lake south of Gainesville. I don't remember its name but it was almost dead. Heavy rains had brought in large amounts of tannen which had absorbed all of the oxygen. We did get one 13 pound LMB but very little else.
Do you have any fish left in your lake or might you have lost all of them? Members from the SE can advise you better than I. I suggest you have your lake electrofished to see what you really have.
