I would nymph, as I see is the case.
As far as water types, try to find slow steady current that is around three feet deep... just like the hatchery tank. It's the type of water that they are used to. It takes the trout a fair amount of time to spread around and start holding in water that is shallower with faster current. Also, do not neglect midges. Midges hatch in the hatcheries and stocked fish know what they are. Small flashy stuff can work great on new fish. Also, small streamers can work great at times, but fish become numb to it after a few minutes of it.
Hope this helps!