I am not sure I agree, with a large, deep pool achieving clarity requires removing suspended "stuff" through the filter. In an ideal world one might be able to tag a cubic inch of water and track its migration through the pool, plumbing, pump and filter but its probably more likely that some parts of the pool circulate more than others, like the ocean of like a particle of air. I guess one way to check might be to drop a piece of tinsel or black dot of plastic 1/4 inch in diameter as far away from the drain as possible and see how long it takes to migrate and get sucked into the drain. I might be nerdy enough to try this but I am also certain a bird would fly by and my attention span would cease....
