We don't have ducks but our back-fence neighbors do! I've told them about them--they hit early morning late afternoon.

But when their automatic pool cleaner is in, the ducks stay away. I don't know what kind it is--I think it's pump-assisted, definitely not a robotic.

Their fence is VERY far away from the pool...basically the back yard is fenced and they have a huge patio. We, OTOH, have the fence very close to the water, which, I believe, makes landing and taking off for the ducks tougher.

Funny, because here ducks are rarely a problem and not that common in suburbia. Usually it's geese that are like giant flying pigeons and each one makes almost as much of a mess as a small beagle. But they haven't been around as much lately, unlike the infestations we had in years past.