New Build Question: Pipe Sizing and Skimmers

Sam and fam

New member
Apr 27, 2021
3
Dallas, TX
Pool Size
12250
Surface
Plaster
Chlorine
Liquid Chlorine
Hello - New to the boards and I have been absorbing as much info as possible on maintaining the pool but as I am now getting construction plans I am starting to fall into the bottomless pit of the overwhelming amount of info out there on plumbing (well everything pool related). Nonetheless, there is tons of info out there and so many experts, I am not one (first-time pool owner to be), and I was hoping to get some perspective and guidance. I am building a small geometric gunite pool (12,250 gallons) in N. Texas (basic info: no trees, full sun all day, planning to do liquid chlorine).

I reached out to my builder to inquire about doing larger pipe sizing and possibly adding a second skimmer. The response doesn't seem to be saying I can't but I just thought I would get more info as it sounds like I may not necessarily need to.

My questions to the builder/salesperson and their response: (Does this sound right or should I push to make the changes to match return to suction and add the 2nd skimmer)


Question: I was curious about plumbing lines, I know you mentioned 1.5-inch PVC lines were the standard, I see many of the Jandy pumps recommend at least 2 inches and the flow rate is much better on 2 inches, is it even possible to request 2 inches?

  • Answer: That is referring to the suction and we use 2 1/2 inch plumbing so we are good there. For the returns, the industry standard is 1 inch and that is where we use 1 1/2 inch.

Question: Are we able to add a 2nd skimmer? I see we have 1 listed but I would prefer to have at least 2.

  • Answer: We definitely could do 2 skimmers but it really wouldn't help. If you had 2 skimmers, then, it's sort of a waste to have a variable speed pump because it would always have to be running at a higher level to have enough pull to make both suction useful. Currently, you have 1 skimmer and 4 returns, you can upgrade to 2 skimmers and 6 returns but on the lower settings of the variable speed pump (which helps to save you money), you will have very little water coming out of the last 2 returns unless you crank the variable speed up which defeats the purpose of having a variable speed. Does that make sense? 1 skimmer is truly sufficient for your size pool but I will do whatever you would like. To upgrade to 2 skimmers, it would be an additional $850.

Thanks for any and all guidance.
 

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HermanTX

Gold Supporter
May 20, 2020
2,647
Katy TX
Pool Size
14600
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Chlorine
Liquid Chlorine
Welcome to TFP.
My pool is just a bit bigger than yours and I have 2 skimmers (and a main drain). Wind direction has a lot to do with adequate skimming so I would go for 2 skimmers. Also, should there ever be an issue with one of the skimmers then having that second one is great. Also, and this is very important, suggest you have that second skimmer with its own independent line back to the equipment pad. This way you can control how much suction each gets. I am thinking your PB will tie them in series (on a common 2.5") line back to the equipment pad but if you have 2 separate lines (each one is 2.5" for each skimmer) then you can better control the suction from each. You will need a valve where they come together at the equipment pad. So you will actually have 3 suction lines - 1 main drain suction and 2 skimmer suction lines. You will have a valve between the main drain and the skimmer (as shown in the current drawing) but another valve separating the 2 skimmers.

BTW - your plumbing drawing shows 2.5" suction on main drain but only 2" on the skimmer. Also, it shows 2" on all the returns - so what the PB says and what the drawing shows are different.

I do not think you need 6 returns - stay with the 4 and add the independent skimmer. You will be fine.
Also the PB commented that 1" return is the standard - that is very far from the norm - you should have minimum 1.5" returns to the pool.
 
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needsajet

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As far as the argument that two skimmers defeats the value of a variable speed pump, I don't agree.

First up, the main drain can be throttled down very low, just enough so that a small amount of water flows through that line keeping it free of algae, and for the pool water mixing value of a main drain. Most of the flow will come from the skimmer(s).

As mentioned above, a second skimmer allows more flexibility to allow for wind either changing day to day or seasonally, and if it turns out that the single skimmer location wasn't the best. You'll very likely end up with one skimmer doing most of the skimming, and the second being throttled down most of the time. So you end up running your variable speed pump mostly for the skimmer doing most of the work, almost the same circumstance as having just the one skimmer. If wind is helping with skimming more of the time, you could even save power by not needing as high a flow to capture the debris.

All this depends on each intake being piped back to valves at the equipment pad, so you have the control flexibility, as mentioned by HermanTX above.

1" is not standard industry practice for a swimming pool circulation system. Just take a look at what's sold in a pool shop. You'd have a hard time finding much selection of one-inch fittings. It would theoretically work if each return had its own line, but that would be overkill in the circulation system. I've seen 1" used on in-floor cleaning systems, and that's about it.

If it were mine, I'd just ask for 2" throughout, with 1.5" OK'd if only going to a single return, for example at the end of a pipe run that's shared with other returns. For the main drain, 1.5" would be fine as well, because it's not used at a high flow rate for enough hours to provide any monetary gain from efficiency. Maybe that could be used for bargaining with the PB. The extra cost for extra skimmer doesn't seem horribly out of line, because that's the cost of the skimmer itself, plus positioning it in the concrete, finishing around it, and so on.
 
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Sam and fam

New member
Apr 27, 2021
3
Dallas, TX
Pool Size
12250
Surface
Plaster
Chlorine
Liquid Chlorine
Welcome to TFP.
My pool is just a bit bigger than yours and I have 2 skimmers (and a main drain). Wind direction has a lot to do with adequate skimming so I would go for 2 skimmers. Also, should there ever be an issue with one of the skimmers then having that second one is great. Also, and this is very important, suggest you have that second skimmer with its own independent line back to the equipment pad. This way you can control how much suction each gets. I am thinking your PB will tie them in series (on a common 2.5") line back to the equipment pad but if you have 2 separate lines (each one is 2.5" for each skimmer) then you can better control the suction from each. You will need a valve where they come together at the equipment pad. So you will actually have 3 suction lines - 1 main drain suction and 2 skimmer suction lines. You will have a valve between the main drain and the skimmer (as shown in the current drawing) but another valve separating the 2 skimmers.

BTW - your plumbing drawing shows 2.5" suction on main drain but only 2" on the skimmer. Also, it shows 2" on all the returns - so what the PB says and what the drawing shows are different.

I do not think you need 6 returns - stay with the 4 and add the independent skimmer. You will be fine.
Also the PB commented that 1" return is the standard - that is very far from the norm - you should have minimum 1.5" returns to the pool.
As far as the argument that two skimmers defeats the value of a variable speed pump, I don't agree.

First up, the main drain can be throttled down very low, just enough so that a small amount of water flows through that line keeping it free of algae, and for the pool water mixing value of a main drain. Most of the flow will come from the skimmer(s).

As mentioned above, a second skimmer allows more flexibility to allow for wind either changing day to day or seasonally, and if it turns out that the single skimmer location wasn't the best. You'll very likely end up with one skimmer doing most of the skimming, and the second being throttled down most of the time. So you end up running your variable speed pump mostly for the skimmer doing most of the work, almost the same circumstance as having just the one skimmer. If wind is helping with skimming more of the time, you could even save power by not needing as high a flow to capture the debris.

All this depends on each intake being piped back to valves at the equipment pad, so you have the control flexibility, as mentioned by HermanTX above.

1" is not standard industry practice for a swimming pool circulation system. Just take a look at what's sold in a pool shop. You'd have a hard time finding much selection of one-inch fittings. It would theoretically work if each return had its own line, but that would be overkill in the circulation system. I've seen 1" used on in-floor cleaning systems, and that's about it.

If it were mine, I'd just ask for 2" throughout, with 1.5" OK'd if only going to a single return, for example at the end of a pipe run that's shared with other returns. For the main drain, 1.5" would be fine as well, because it's not used at a high flow rate for enough hours to provide any monetary gain from efficiency. Maybe that could be used for bargaining with the PB. The extra cost for extra skimmer doesn't seem horribly out of line, because that's the cost of the skimmer itself, plus positioning it in the concrete, finishing around it, and so on.
Much appreciated, I will reach out and work to get the 2nd skimmer added and ensure that it is on its own independent line back to the pad.
 
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HermanTX

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May 20, 2020
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Katy TX
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Liquid Chlorine
Now that the skimmer discussion is over, you may want to consider how you want to chlorinate your pool. I see the PB has an inline chlorinator - which uses pucks. That is not the best method over the longterm. If you read up on TFP methodology you will understand why. ABCs of Pool Water Chemistry and

The inline chlorinator is inexpensive and pucks are widely used my many (although there is a looming shortage if you listen to the news due to the disabled plant down in Louisiana). A Saltwater Chlorine Generator (SWCG) would be the better option. It is more expensive upfront and many PB in Texas do not offer SWCG but it is widely accepted as a easy and less maintenance method to chlorinate your pool. You should search the forum and seriously consider it.
Read - Salt Water Chlorine Generators - Trouble Free Pool
 
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Sam and fam

New member
Apr 27, 2021
3
Dallas, TX
Pool Size
12250
Surface
Plaster
Chlorine
Liquid Chlorine
Now that the skimmer discussion is over, you may want to consider how you want to chlorinate your pool. I see the PB has an inline chlorinator - which uses pucks. That is not the best method over the longterm. If you read up on TFP methodology you will understand why. ABCs of Pool Water Chemistry and

The inline chlorinator is inexpensive and pucks are widely used my many (although there is a looming shortage if you listen to the news due to the disabled plant down in Louisiana). A Saltwater Chlorine Generator (SWCG) would be the better option. It is more expensive upfront and many PB in Texas do not offer SWCG but it is widely accepted as a easy and less maintenance method to chlorinate your pool. You should search the forum and seriously consider it.
Read - Salt Water Chlorine Generators - Trouble Free Pool
Thanks. A SWCG is certainly the common choice here in TX but I was planning to swap the tab chlorinator with the HASA "The Liquidator".
 

HermanTX

Gold Supporter
May 20, 2020
2,647
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
A SWCG is certainly the common choice here in TX but I was planning to swap the tab chlorinator with the HASA "The Liquidator".
I don't know much about it but be interesting to hear your results if you install it.
See this thread I found on TFP
 
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