Requesting expert feedback on return lines, skimmer placement, and sheer descent GPM flow - owner/builder


New member
Nov 14, 2020
Hi TFP community:

I am a rookie to this site and pool building in general. I told my wife for 10 years we’d get a pool and was able to delay it until now. My kids are now 8 and 10, and now it seems I am out-voted 3-1 in my household; The family wants a pool for the hot Phoenix summers; I can't blame them since it's hot here in the summer! I don’t want to hire a commercial pool builder, and I’d rather do the research and sub-out the work and owner/build it. I have a friend who contributes to this site, and he owner/built his pool 10 years ago so I plan on doing it myself too. I look as it as an enjoyable challenge.

TFP is a great site to read and learn. I feel like I have studied for a final exam and now (hopefully) have a good idea on how to build a pool based on independent research coupled with TFP information. Maybe everyone doesn’t agree 100%, but I have read good posts like having two skimmers versus one in case one skimmer breaks (and also how two skimmers achieve overall pool cleanliness) as well as having closed loop plumbing to ensure consistent pressure to the farthest return.

I want to build a 30’x16’ (15’ in the middle, 19’ at the baja shelf) play pool. It’s not too deep – basically a baja shelf 12" deep then the pool 3.3 ft to 5 feet deep. I have a somewhat sloped lot and already did the pre-grade. I will have a 18” raised bond beam for about 30-35% of the linear footage of the pool. So I plan on taking advantage of the raised bond beam and installing three 36” sheer descent waterfalls for good visual and sound.

Unfortunately, pool plumbers are hard to get in touch with in Phoenix right now. Those that I have been able to make contact with simply tell me to email my plans for a bid. In the “old days”, I would have talked face-to-face with my pool plumber to discuss my plans and ensure I was on the right track. Unfortunately in 2020, pool plumbers are very busy and the face-to-face consultation is not going to happen.

Today I put together a proposed plumbing plan. I would really appreciate all feedback from the experts on TFP. To be upfront: I will only use the sheer descents every once in a while. Maybe when covid is over and I have a party or friends over, I would turn the waterfalls on. Or if we as a family are swimming, I will turn the waterfalls on for fun. Other than that, I probably won’t use the waterfalls all that much to be honest. I am going with two venturi skimmers and 5 “traditional returns" (I am not counting my sheer descents as “traditional returns”).

Questions for the TFP experts: Do my placements of the 5 “traditional returns” look good or do you have different recommendations for placement? I also placed the two venturi skimmers on the same side of the pool because I thought putting a second skimmer on the other side of the pool would simply be too far from the pump.

Finally, regarding the three 36” sheer descent waterfalls (the 3 sheer descents are spaced 24 inches apart from each other), I believe based on what I have researched I am ok with the 3HP VS pump utilizing the 3 way diverter. When using the three sheer descent waterfalls, I plan on shutting off the 5 “traditional returns” and only turning on the dedicated return line for the sheer descents to have good flow at the waterfalls. With a 2.5” or 3” inch PVC pipe dedicated for the sheer descents coupled with the Pentair 3HP VS, I will need 108 GPM minimum for good flow to the three 36” waterfalls. I have about 60 feet of pipe from the 3 way diverter to the farthest waterfall (I think the 60 feet of pipe is the “head”). Based on the performance curves published at IntelliFlo High Performance Variable Speed Pool Pump, I think based on head / GPM ratios for the 3 HP pump, I will achieve good flow between speed 4 (3150 RPM) and max speed 5 (3450 RPM). I also want to use a larger 2.5 inch or even 3 inch PVC pipe to reduce the friction and in essence not have to run the pump at such high RPMs to achieve good flow at my 3 waterfalls. I assume increasing pipe diameter reduces head but I am not 100% sure.

TFP Experts - please comment on my sheer descent reasoning because as I said I am new to this and have studied for this exam in pool building over the last weeks and want to get it right (or as right as possible). 😊

Thank you. The plumbing plan is attached for reference. I appreciate all feedback!!!


  • Plumbing_Plan_11_22_20-converted.pdf
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Bronze Supporter
Sep 3, 2018
Gilbert, AZ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Are you sure you only want it 5’? It’s going to be awfully warm in the summer.

We are also doing o/b. Plumbing was the last bid we got any for but did get a few back. Our pool consultant drew the plans and then emailed them to a lot of subs who emailed their bids back to me. They did just give the bids based on their knowledge but 1 of them spoke to my husband about some things and the other emailed back and forth with me about things. It didn’t seem like either of them would have had a problem meeting with us. The one I emailed with said if I wanted something specific our architect would usually send it to him. He offered to draw one up for if we wanted to see what he had in mind. If you want a few names I can send them to you. The one we are going with is also doing steel, electrical and gas. Our friend used the other one we thought about and really liked his customer service.


Silver Supporter
Jul 29, 2018
Katy, Texas
The sun shelf--or whatever you call it--was a total waste of pool perimeter for us. We NEVER use it. I agree with 5' deepest end. We did six feet (wife's insistence) and now we both agree six feet was a mistake. Most people it seems really want to stand, and not many can stand in six feet of water, plus I'd like to be able to rescue a kid while standing on the bottom. Finally, prevailing winds. Check. We have about 10.5 months of wind from the south and the rest from the north. Doing it over again, I'd build an oval pool with a skimmer at the south and one at the north ends. Then in place of the useless sun shelf, I'd have stairs across the shallow end, as we find people also want to sit in the pool, and different people sit at different levels. Stairs all across would allow for a bunch to sit while still having room for someone to walk down into the pool. Also consider two pumps. VSF for the filter and returns. Whisperflo for the water features. That way you don't have to run the water features to run the filter, and the filter pump can run a low economical speed. Again look where the wind blows and put your skimmers there, because that's where debris is going to end up anyway.


Well-known member
May 19, 2020
San Antonio, TX
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Hi, I see you have a Pentair pump with a Hayward Filter. Probably better to have the same brand for your equipment. I know there are many here that can help with equipment choices!
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