Quote Originally Posted by DennisP View Post
And I thoroughly disagree on your "conclusions"... Even with just over 4ft of water I can tell a difference in temp between the upper levels and the bottom without the main drains. With them on it is drastically different.

I would argue your assumption that since chemicals mix that temperature variances are also nil. That is far from the case.

Again, believe what you want. I have direct observation and quantifiable results to backup what I have posted. And unless you have the exact same pool setup, in the exact same environment, you have no point of reference other than flawed studies to fall back upon. I am an engineer, but far from blinded enough to think that those are the only answers and fully realize there are environmental factors that change everything compared to a set of "fixed examples". Your diatribe on pump dynamics show that you understand those aspects of engineering, so why be so obtuse on this???
Oh, I don't follow your ideas Dennis and your Facts are not really facts they are as you see it but not facts.
Of course you get better flow with you M/D's as you don't have more than the 1 skimmer? how can you possible get the same flow with 1 skimmer compared to when the M/D's are involved?
As to the M/D's getting your pool up to temperature, it depends where your thermometer is. I have the pleasure of playing with pools set up like yours and also ones I have put a 3 port valve on so I can switch the M/D's from inlet to outlet.
Now you believe taking cold water from the bottom and feeding it into the top via returns is quickest. I don't, the water at the surface is warmer (fact) take the water from there and it takes less energy and therefore less time to heat that up than the colder water from the bottom that's a fact to. feed that into the bottom of the pool via the M/D's and the lower part of the pool gets warmer quicker as you said it causes things to mix quicker, yes it does whether it's used as an inlet or an outlet is mixes more that's a fact, you've agreed, I have tested it, it follows physics and you can't mess with physics.

The daft thing you said back a few posts about taking out your other return and wishing you hadn't put it? Go for it Mr engineer! then you'll loose performance as the friction and restriction you'll place on the system will create a great big headloss. You cannot compress a liquid so you can only get into the pump via skimmer and M/D's what the return line will allow to flow, the headloss and friction is just wasted energy.

I am not bemoaning M/D's, I was amazed that pools without them worked at first, the guy who taught me thought as you did. My pool doesn't have a M/D but I don't have a robot cleaner either as I don't need it a net and a pool Blaster Max is all I have and the Max is only for shear quickness as there is bound to be one leaf that misses the skimmers but my debris is taken out before it sinks in most cases but you are right I have to empty my skimmers more often.

Dennis where is the floor in the studies? they use the same software that keeps planes in the air and the maths behind it is very very accurate, the same is used in films to generate waves and fluid movements?
You need a study to prove it's floored, is there one?