Betcha Bek Ko is right when it is time for a siene for the Persimmon ponds, but isn't the problem now a bit trickier? 17 x 8 x 4 and 3/4 covered? You should be using your koi net with a 9' handle and it would still take all day for the little fast goldfish. A siene will be near impossible to use with the cover on.
I do have 2 of AES's sienes. One is the cheapest and is the cheapest. One was only slightly higher in price and works just fine for my ponds. Bubba wil have fun with his end.
Perhaps what you need instead is a trick. Come out at night with a flashlight and your skimmer net. Might be easier to net them when they are asleep.

I know, I know, sounds goofy but it works.
Mickey the windowman