Thor welcome to the forum, 3 acres is a nice size pond but as others have said that 5.5ft depth is the problem.
Are you planning to have aeration or do you have some means of pumping water into the pond?
The winter is my big problem cause trout require good oxygen and my pond is max 8ft. deep. but the 95 GPM gravity inflow allow survival in the summer.
I can tell you though that Pumpkinseeds and Golden Shiners seem to handle tough winters, Yellow Perch are suppose to handle low oxygen but I don't know how well Crappie can take those conditions.
