Not at all... It is a very simple principle that you have been arguing against aimlessly for this entire thread. Simple, cool water sits at the bottom. Warm water at top. Cool water gets sucked in, warm water gets injected. Complete turnover with the shortest amount of time. You will NOT have that without pulling water from the furthest, lowest point of the pool while returning water at a higher further point away. C'mon, how hard is that to understand??!?!?!?

Basically you are trying to say the sky is not blue because you are color blind and a study by color blind people is stating that the sky is mauve... I am not color blind, I know the sky is blue and I know what happens in my own pool. I pay my heating bill. I have a HUGE financial motivation to make sure I get the quickest result in the shortest time.