I'm always in search of the "perfect pond" for a particular species, so I think this is a very important question.
Believe it or not, I think that the perfect trout pond in any kind of marginal climate is actually a "series" of smaller trout ponds. Cecil has proven again and again what incredible trout can be grown in tiny ponds. I think the key to water quality is the ability to completely replace the water on a regular basis, and a great way to do this is injecting well water. Because of the inherent cost of pumping water I think that my perfect trout pond would be four separate 2,000 sf ponds, each with it's own dedicated water source, then all draining together into a yellow perch pond. This would be the best of all worlds. Plenty of fresh cool water for the trout, and a nice semi-cool fresh water source for YP. Individual smaller ponds would also limit your risk to total die-offs, and create opportunity to raise different species of trout.
Just my .0000000000002 cents worth.
