I have a cichlid pond, it is up spring thru fall here in Wisconsin.
My best success has been with Uruguayan cichlids because they can take the dramatic temp changes common here.
Gymnogeophagus, Australoheros, and Uruguayan Crenicichla have worked best.
I tried some Central Americans without the same success, all it takes is a few cool nights in June, and fish are floating.
Although cichlids are colorful from the side, from above they tend too disappear, and I can sometimes go days without seeing them.
I have also found raccoons to be very adept at eating them if the sides of the pond are not steep enough, and the pond too shallow. I found those pre-form ponds sold at hardware chain stores to be perfect lunch counters for hungry raccoons

The pond below hold about 1000 gals and has my Gymnogeophagus this summer.
