What is "Hydraulic Design"?

[South_Texas_Sun]

Hi Carl, thanks for the reply.

You said, "Pressure and water flow through the pipes and in the pool matters--so location of the skimmer(s), low drain(s) and returns are all important."

We have a slightly sloped hill behind the house and they're building a freeform 12 to 20' foot by 40' foot pool with the hottub at the top of the slope and a "cold tub" grotto feature next to the hottub/waterfall area.

The PB admitted that the grotto feature tends to get dirtier than the rest of the pool, so he plans to put in a second drain at the bottom of the grotto. (There's spa jets in the grotto/"cold tub")

Do you think this is going to present any special problems for pumping that I should ask about?

The reason I'm asking all these questions is that I tried "Googling" for this kind of info and came up pretty much empty handed. The PB is a smaller company and I'm not sure how many pools like this he's actually built because there's not a lot of pool co's that offer this design unless you ask for it. Our fellow seems talented and anxious to please, but is learning as he goes and admits that, so I'm hoping to shorten his learning curve BEFORE he finishes our pool. lol

Thanks again.

[Poconos]

My guess on 'hydraulic design'? As Carl said flow both thru the pipes and in the pool itself is important. I suspect the term is used to indicate that the pipes are sized and routed to minimize flow resistance. ex: swept bends vs. sharp 90's etc. The builder is right about 90's making it easier to fix a problem. However, by oversizing the pipes the bends and routing become less significant. The difference in cost between pipe sizes is small so once you dig, put in the largest reasonable size.
Al

[South_Texas_Sun]

Hi Poconos, thanks for the reply.

Like you, I come from the "bigger is better" school for most things, and when asked, our Pool Builder said that he used 2 1/2" pipe.

Now, if you've ever siphoned gas out of a car, you probably realized that "too big" is much worse than "not big enough" unless you can get enough suction........ (insert veiled double-entendre here....lol)

Is there a book on pool hydraulics or some way to get a little smarter on the subject without building a few hundred pools?

Since our pool project is slightly UPhill from the house, I'm pretty anxious to get it right the first time on drainage and plumbing issues.

Thanks again.

[Poconos]

Siphoning gas is a lot different than the suction line on a pump. You have limited lung volume capacity. If you're thinking of the pump priming sequence, the pump pulls a slight vacuum (self-priming) so the size of the pipe won't matter. It still pulls the same vacuum independant of suction line size.
Al
BTW: Know of no books on the subject other than technical fluid dynamics stuff. Perhaps some of the plumbing books get into this without going into the 'why' but I don't know.