Those are some beautiful ducks,what breeds are they? We have muskovies,saxonies,blue pied and some very colorful black cayugas with a nice rainbow sheen when seen under the sun.
Now there are some ducks living it up in style....god don't let my wife see this or she will be out combing the for sale adds for a hot tub or swimming pool for our spoiled flock,lol. You can make your own 5 gallon bucket filter like they do for diy ponds with koi that would probably do a good...