Dbremer, hi from another Minnesotan, sounds like a great pond. Just wanted to chime in on a couple of points. First, you better recalculate your water volume. I figure a 5 acre pond that averages 6 feet deep is like 11 million gallons. By the way, there is a handy conversion tool you can get off the internet called "Convert" you can get it at
http://www.earthsci.org/freewar/freewar.html It does every general type conversion you could ever want I think.
Second, have you checked into using retonone here in Minnesota. If it's like anything else you'll need a permit and probably have to hire a licensed applicator. I have a friend who's best friend is one of the Minnesota fisheries guys. He's checking on this for me so I can make plans to clean up my pond one day if needed. I can let you know what he says when I find out. Maybe even find a source for retonone if they allow me to DYS. I made the "mistake" of putting crappie in my 1/2 acre pond. As to whether this was a mistake we'll find out as time goes on. I do manage it intensly by removing hundreds of young crappie each year and making sure I have predators. Based upon what I've learned from the experts on this forum I think that a smaller pond like mine is easier to manage for crappie than your 5 acres would be because I at least have a chance of taking a high percentage of my crappie out. You will never catch enough to dent the population. I have so far caught 3 year old crappie that are around 11 inches. By the way, you also need to consider that if you plan to manually manage the crappie by trapping or catching them in mass you should know that this is illegal in Minnesota, even in your own pond. So if your pond is visible from roads or neighbors you may not get away with trapping them too long before a warden notices the traps.
Eventually the subject of how to aerate is going to come up. All I have to say about this is despite much advice to use a bottom diffuser in deep water in the summer and shallow water in the winter I have a bottom diffuser right on the edge of my deepest water at 8 feet. I have never lost a fish to any kind of kill either winter or summer. But I will admit that this may be dumb luck or the fact that I don't run the aerator 24/7. I have found that two 4 hours shifts per day at 5 cfm is enough. If you scan all past posts on aeration I think you'll discover that folks on this forum have concluded that aeration really doesn't add much O2 to the water anyway. It mainly serves to prevent stratification and to keep surface water moving in the summer so natural exygenation can occur and it also keeps the ice open in winter for natural oxygenation and also so that bad gases can escape. I think I've found the balance in my pond that allows me to accomplish these things with a deep aerator without supercooling the water in winter. My 4 cents.
