I have a large pond that can stock a large number of fish however I may not always stock too many. So I have come up with a filter system that can be bypassed depending on how much fish I am stocking. My current idea is to have a swirl filter that then goes to a sand filter filed with zeolite that then goes to grow beds and back to the pond. Each part of the system can be bypassed depending on desired filtration.

I'm wondering where I should put the pump?

If i place the pump before the swirl filter I am concerned that the sand filter will not have enough pressure. If I place the pump between the swirl and the sand filter I'm not sure if the swirl will work - what would keep the water flowing into the swirl filter?