That was exactly how I found out the mix sucked, by test readings and putting a dye in the pool... I could put it in on the far end and it would slowly sink and dissipate, but a half day later you had a blue blob directly under where you dumped it in. And that was without a filter in the bigger pump, so it was really sad...

Oh, I gotcha in regards to the skimming flow, in these discussions I always "assume" there is valving in place (I never do anything "half-way" and everything will be able to be turned on or shut off), so even with multiple skimmers, each skimmer would have a valve on it. The only item I considered not going that far is with dual main drains, and that is having them tee'd together and a single 2" run from the tee to a valve...

Ok, well the drains will be here tomorrow and I will have to decide if those are going in or not... I do believe I will put in the extra returns though...