There's no reason you can't use a 20 foot pond as a holding pond. If you plan to stockpile fish, be sure there's no vegetation in it. Several reasons for this suggestion. First, most shiners spawn on rooted aquatic plants, and you will end up with many undersized babies. Second, if you ever want to seine the pond, vegetation gets in the way. Plan to aerate, too.
Design your pond where you can wade from the shoreline, but try to get the slope as close to 3 to 1 as possible.


Teach a man to grow fish...
He can teach to catch fish...