Actually, I didn't miss that at all... But, that is all static condition stuff. My point is a large body of water is a dynamic environment and what is wrong with the option of being able to draw from the bottom if you want?

Ideally that is the way I am viewing it, another option for mixing the water. Sure, for static condition it doesn't matter much, but what if I want the main drains to do all the work any no skimmer action? What if I want to heat the pool and pull only water from the bottom to accomplish that?

I mean what is the point of having all these valves unless you can pick and choose the configuration you want at a given time?

From a "I maintain other peoples pools" I can FULLY see why a main drain setup is unnecessary. But, from a "I maintain my own" perspective I can see all the options alowing you to experiment and determine the best possibe methodology that works for you.

Having all this data is great, but only what you put into practice really matters.

Could I skip the main drains and have a nice pool? Of course.

Could I even say forget it and put in no extra returns as well and rock a pool with only a singe skimmer and return? Of course.

But, the whole point is, why not add the rest?

Again, I fall back to the inground vs above ground issue. You will never find an in-ground pool of even the most simplistic design that is 10k gallons or bigger with only one return and one skimmer. Just does not happen. So, why is it the "standard" for above ground pools even double that size or more? (and yes, I understand the "simplicity" factor of above ground vs inground, but that does not apply in my case, obviously)

I am viewing main drains as the ability to pull water, when you want, from another location in the pool. Yes the returns can be looked at to "mix" the water, but with the pump on low that ability is greatly compromised. The studies say nothing about that kind of situation. And you cannot tell me that pulling from the bottom of the pool and returning to the side, on low wouldn't provide a better mix than a return and skimmer within a couple of feet each other. That is my whole point. It is not about the effectiveness of the skimmer or the drain as individuals, it is purely about being able to provide a better mix at a lower pump speed.