don’t start feeding the fish until the water temperature gets up to 50 degrees F in the spring. There are some excellent articles on the Web about the proper feeding of pond fish.
When winter comes and the temperatures start to drop, the fish head for the bottom of the pond and basically go into a state of hibernation. They may appear to be dead, but they’re not, and they will survive the winter very well. This is the main reason to dig the pond deep enough, so they’re protected from not only the weather, but also from predators such as the Blue Heron.
I honestly can’t tell you about fish diseases. Since we dug our first pond about eight years ago, we’ve only lost two Comets, so we feel that disease hasn’t been a real problem for us. Again, I’m sure that if this is a subject you want to research, the Web would the place to check.
The last picture above is our turtle that we have had for about six years. He was the size of a silver dollar when we got him and when we put him in the pond our big Koi swallowed him almost immediately. Evidently he turned out not to be the Koi’s favorite snack because the fish spit him back out and he’s been around ever since. He goes to the bottom and stays with the fish in the winter and shows up again each spring.
The one last thing I would recommend is that if you decide to get fish, get them new rather than from a friend’s pond. This lessens the risk of health problems. If you want to get a good book about fish and how to raise and care for them, check out
FantasticFishPonds.