A big pump that is throttled back with a ball valve will actually use less electricity to move the same amount of water. Also it is a good idea to put an anti-siphon valve in the return so that it can't back flow. That way you can have one lower or aim down with loc line or something.
I agree with you; I think you are misinterpretting what I said. I said a larger pump will cost more to run than a smaller pump. An appropriately sized pump will typically cost less to run than an oversized pump valved back, all else being equal. I would say this is far more often true than not.





