Help with pipe sizing please

DIYCypress

Member
May 1, 2019
11
Texas
Sorry for the double post. I couldn't figure out how to move it.

Completely new construction and looking for help sizing the plumbing/pumps accordingly. I am planning on all Pentair equipment, most likely Pentair 011018 variable speed pumps, 1 main/spa pump and 1 water feature pump. I am using dedicated Paramount 360 Unblockable drains (which suggest a 2.5" minimum plumbing run) and 2 Paraskim Venturi skimmers (which require 2" suction, 1.5 venturi return). Pentair 520 square foot cartridge filter with up to 150GPM flow. Pool is roughly 650 square ft, 18500 gallons, geometric with 7.5 deep end. I want to use the Spa while also using the water feature. The spa is slightly oversized and I am trying to figure out how many jets I can plumb in the spa. Planning on 8 individual waterway jets with a 2" water loop, 1.5" air loop in the spa and two 3 jet manifolds for 14 total jets at around 10-12 GPM ... knowing that I will probably have to close off either the individual waterways or the manifolds to get proper flow. There will be an air blower as well.

1) If I run a 3" suction/3" return to spa and then reduce to 2" looped in the spa, what is the max number of jets I should use at a time? Any issues with plumbing like I described above and only using max number at a time? Thought is to have 3 jet manifold for wife and I and then singles for when we entertain.
2) Planning on running 2" suction from each skimmer and probably 2.5" main.
3) On the returns, my last pool was horribly balanced. I have no idea how it was actually plumbed as it was 10+ years old. With using the venturi skimmers I want to be able to control the return flow to them so at a minimum I plan on running a dedicated 2" return to the set of skimmers and T to the middle of the two using 1.5" pipe (what is recommended by Paramount). For the regular returns I plan on plumbing two other sets of 2" then T to 1.5", 1 set to shallow end and 1 to deep end, all with valves. Then a 2" valved spa return. Is that complete overkill? The difference in cost is minimal in the grand plan but is a simple 2" looped return actually better?
4) Water feature I have a 90GPM for a six foot water feature and then 2 water bowls at approximately 15gpm each. I was planning on running a 3" suction, and then 3" return to the 90gpm and 1.5" to each of the 15gpm, all valved off a dedicated pump. I may also add a couple bubblers but we haven't decided on that but was thinking two 1.5" bubblers on a 2" run.
5) 1.5 Polaris Booster pump
6) 3/4" auto water level

Just basing this off the flow capable of PVC size without calculations for head loss. Spa suction is roughly 35feet from pad which flows in to deep end.

Any suggestions on plumbing size/suggestions I am all ears.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,800
Pleasanton, CA
1) If you had a dedicated spa jet pump, you might get 120 GPM out of the pump. With the filter and heater, more like 100 GPM total. So if they truely are 10 GPM jets (i.e. 1/4" orifice), then you could get up to 10 running in your configuration.

2) I would go with all 2.5" on the suction. No reason not but a lot reasons to do it.

3) Loops don't buy you much around the pool especially with small pipe. If equal flow is the goal, just go with larger pipe. It minimizes the pressure differential between returns.

5) Why not go with a robot instead?
 

DIYCypress

Member
May 1, 2019
11
Texas
1) If you had a dedicated spa jet pump, you might get 120 GPM out of the pump. With the filter and heater, more like 100 GPM total. So if they truely are 10 GPM jets (i.e. 1/4" orifice), then you could get up to 10 running in your configuration.

2) I would go with all 2.5" on the suction. No reason not but a lot reasons to do it.

3) Loops don't buy you much around the pool especially with small pipe. If equal flow is the goal, just go with larger pipe. It minimizes the pressure differential between returns.

5) Why not go with a robot instead?
1) Thats about the max I would expect. Has anyone installed extra jets knowing some will have to be closed to get proper flow?
2) 2.5" over the 3" on the spa suction? Why is that? Does the pad plumbing restrict to much to make 3" not worth or? Or were you referring to main and 2 skimmers?
3) Does running 2.5" pad plumbing make a large difference?
4) Considering the venturi skimmer I'm going to run dedicated returns with valves. Its a little extra work but have the option of balancing as needed.
 

DIYCypress

Member
May 1, 2019
11
Texas
1) Thats about the max I would expect. Has anyone installed extra jets knowing some will have to be closed to get proper flow?
2) 2.5" over the 3" on the spa suction? Why is that? Does the pad plumbing restrict to much to make 3" not worth or? Or were you referring to main and 2 skimmers?
3) Does running 2.5" pad plumbing make a large difference?
4) Considering the venturi skimmer I'm going to run dedicated returns with valves. Its a little extra work but have the option of balancing as needed.
And not doing a robot as I don't like the idea of having to put in and take out. In our old pool we liked the option of leaving it in the pool all of the time and only removing when we would go swimming.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,800
Pleasanton, CA
1) I'm not sure but I can almost guarantee that if you add more jets, at some point you will want them all to run at the same time. You might be better off designing the system so you can do that.

2) That was a reference to your #2 in the first post:
2) Planning on running 2" suction from each skimmer and probably 2.5" main.
3) Not that much. There is usually not enough pipe and fittings to make that much of difference. Most of the pad head loss is going to be in the filter and heater. One way to get more flow rate with that setup is a partial bypass around the filter and heater for running in spa mode. Also, a bypass helps reduce problems on high flow rate with the heater and filter.

4) That's fine but there is a potential issue with that if you have all the valves open. The return head loss can become too low causing problems on the suction side of the pump (e.g. air leaks and cavitation). You just have to be aware of the problem and compensate if it occurs.

As for the robot, mine stays in the water pretty much all the time. It has a weekly timer so I take it out once a week to empty it and of course when we swim. So that is no different.
 
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jonpcar

Bronze Supporter
Jun 1, 2016
423
Gilbert, AZ
Cypress...I have an In-Floor-Cleaning-Systm but not sure that I would get another one if I ever built another pool, which I won’t. Here is my input on your plans for your IFCS.

The drain you are choosing is not a debris drain...sure it’s good for dirt, pebbles, seeds...not for leaves or anything larger that make it to the bottom. They will be stuck on that drain...you would need the mdxr3 or the buzztop (or another from a different company) if your desire is to remove larger debris. Your pool location may not have a problem with larger debris. I personally am disappointed I didn’t go for a channel drain when I replastered despite the fact that I get only small amounts of large debris in my pool. If you plan on your maindrain collecting larger debris via the IFCS/popups, you should get a debris container as well so the debris doesn’t make it to the small pump basket.

I’m skeptical of the Venturi skimmers. The literature claims you can now direct 100% suction from the main drain while using the IFCS, and the skimmers will still skim using the Venturi action via their returns. 100% suction from the main drain is a good thing when running your IFCS popups because the main drain is where debris/dirt primarily gets sucked down. BUT, returning water via the Venturi skimmers (in parallel to the popups) reduces the flow of water available to the popups at a given pump rpm, and will not be as efficient or (probably) as effective as simply returning 100% of the water to the popups. I believe there are some exceptions to that, but probably unlikely on modern IFCS systems with larger piping such as yours.

In addition, Venturi skimmers don’t allow a “directioning” of the returned water. One of the most effective changes I learned from others on this board was how to direct my wall returns so that a pool “swirl” developed...and this dramatically improved the effectiveness of my single skimmer. I’ve never actually seen a Venturi skimmer in action (so I might actually be totally wrong here), but their returns don’t seem to be able to support generation of a pool “swirling action”.

My solution, similar to many others who are happy with their IFCS: run popups to clean the pool floor for a few hours a day at high rpm (expensive), and run skimmers at a lower rpm for a longer TBD time to skim (almost free). If you have complete control over the wall returns AND the Venturi skimmer returns, then I suppose there is no harm in installing them (because they can be turned off), but I don’t see a case for actually using the Venturi action on the skimmers, especially since you are planning to install 4? dedicated wall returns as well. During “skim time” on your system, I personally would direct 100% of the return to generating the swirl via the wall returns, and 100% of the suction from your skimmers.
 
Last edited:

DIYCypress

Member
May 1, 2019
11
Texas
Cypress...I have an In-Floor-Cleaning-Systm but not sure that I would get another one if I ever built another pool, which I won’t. Here is my input on your plans for your IFCS.

The drain you are choosing is not a debris drain...sure it’s good for dirt, pebbles, seeds...not for leaves or anything larger that make it to the bottom. They will be stuck on that drain...you would need the mdxr3 or the buzztop (or another from a different company) if your desire is to remove larger debris. Your pool location may not have a problem with larger debris. I personally am disappointed I didn’t go for a channel drain when I replastered despite the fact that I get only small amounts of large debris in my pool. If you plan on your maindrain collecting larger debris via the IFCS/popups, you should get a debris container as well so the debris doesn’t make it to the small pump basket.

I’m skeptical of the Venturi skimmers. The literature claims you can now direct 100% suction from the main drain while using the IFCS, and the skimmers will still skim using the Venturi action via their returns. 100% suction from the main drain is a good thing when running your IFCS popups because the main drain is where debris/dirt primarily gets sucked down. BUT, returning water via the Venturi skimmers (in parallel to the popups) reduces the flow of water available to the popups at a given pump rpm, and will not be as efficient or (probably) as effective as simply returning 100% of the water to the popups. I believe there are some exceptions to that, but probably unlikely on modern IFCS systems with larger piping such as yours.

In addition, Venturi skimmers don’t allow a “directioning” of the returned water. One of the most effective changes I learned from others on this board was how to direct my wall returns so that a pool “swirl” developed...and this dramatically improved the effectiveness of my single skimmer. I’ve never actually seen a Venturi skimmer in action (so I might actually be totally wrong here), but their returns don’t seem to be able to support generation of a pool “swirling action”.

My solution, similar to many others who are happy with their IFCS: run popups to clean the pool floor for a few hours a day at high rpm (expensive), and run skimmers at a lower rpm for a longer TBD time to skim (almost free). If you have complete control over the wall returns AND the Venturi skimmer returns, then I suppose there is no harm in installing them (because they can be turned off), but I don’t see a case for actually using the Venturi action on the skimmers, especially since you are planning to install 4? dedicated wall returns as well. During “skim time” on your system, I personally would direct 100% of the return to generating the swirl via the wall returns, and 100% of the suction from your skimmers.
Thanks for the reply. I actually don't plan on a full in floor cleaning system. I chose the drains as they are unblock able, however I did end up buying channel drains from A&A and will be returning the Paramount 360. I also purchased a Paramount equipment side debris canister as they are true debris removal drains. With having full control over all of the returns and suctions, I should be able to tune it for both optimal suction and movement in the pool. I also have a 6 foot water feature opposite side of the skimmers which will definitely push the majority of the debris to the skimmers and 2 returns deep end and 2 returns shallow end. Figuring I can try to get a good swirl with them or simply direct them to the middle of the pool and let the waterfall also push. Both skimmers are now on the prevailing wind side as well even though aesthetically it isn't the best. The only popups I may use are in a sun shelf/bench as my last pool always had a layer of debris on it. I am installing all jandy valves if I later decide I need to automate even the return action. I figure the complete control over water flow is a small price in comparison to everything else. Im putting a lot of the money I save for contracting myself in to upgrades.