I should have been a little more clear. Step up to 480 to send the power to the pond, when you get there, use another transformer to step back down to 240.

480 single phase motors are available, I've seen them in the oilfields around here. Probably hard to find though.

No matter what route you take, this is going to be an expensive project.

Tom

Few things are harder to put up with than the annoyance of a good example.