Yay! Ducks are great. I got my first pair last September (Silver Appleyards) and now have four adult Appleyards, one big duckling (same age as yours, still with his/her broody mum) and six Cayuga, five Aylesbury and seven more Appleyard eggs being incubated /brooded. Very addictive and husband loves them too (unlike the geese or chickens which he has no affinity with).
Ours don't have a pond (we have one but with an enormous badger sett next to it I reckoned we couldn't secure them sufficiently) but we have a big dog bath they can get in and various other splashing areas. They've just saved up enough from their egg sales to buy another paddling pool (actually it will probably be a builders mixing tray) that the ducklings will be happy in once they're bigger.
I'm lucky in that my ducks all lay first thing in the morning before I let them out, all together in a little nest in the corner of their house. I'd heard they can lay anywhere but mine don't - in fact I've only ever had one egg laid anywhere outside of a house and that was from the goose.
Hmmm, not sure what else to say. I find the ducks the easiest of all my birds - hardier than the chickens and less stubborn than the geese. Enjoy!
H