There's more than one way to skin a cat, and there's more than one way to stock a pond. You're going to get a variety of suggestions, and most likely there will be multiple, workable scenarios. Lots of factors to consider, including your goals for the pond, and how much input (work) you're willing to commit to.
Ever filet a fish and see those black specks in the meat, or the yellow "worms" in the fins, and/or in the flesh? That's where your RES can help you out. They consume snails, which are an integral part of the life cycle of BOTH parasites.
