I have a quad of these little pound cake ducks as i refer to them that said. all this years hatch from spring being the oldest to early summer being the youngest. So first winter, they are water HOGS.. they have 1 40GAL trough and a few smaller type puddle pools as i call them as the youngest in the flock still cannot fly into the big trough, they hate ramps, tried that... they prefer to fly in(they are penned/covered and all full flight) The swimming water is what i need advise on, do they need some open year round?? obviously the larger trough can be equipped to be but should it? i can open ice(have so already ) but eventually it'll freeze to where i could ice skate on it lol The do have a house they go in at night so shelter is not a concern.