Planning Indoor Fiberglass Pool

mareas · Nov 9, 2024

Hello all,

We're planning our indoor pool (14x34x6) and spa (7x9x3) build in an area with no certified PB's and in an unregulated area however I've been trying my best to abide to US/International standards. I'd like to share the process we've made and ask for your valuable feedback!

Climate wise, we live around 6800 ft in elevation in an arid part of North Mexico, it can snow during the winter but have great summers, you can view here for an overview if it helps. The pool will be installed in a steel and block building which we can condition and dehumidify. The mechanical room for the pool will be in another building with better insulation however the heat pump is required to be installed outside.

Automation System: IntelliCenter with Salt Generator + 8 relays + 2 Actuators

Circulation System
Pump: Pentair SuperFlo (max 120 GPM, 13000 gallons) with 3" intake pipe and 2.5" system pipe.
Filter: A 300/400 sq ft cartridge filter (tbd but ideally with 2.5" connections)
Heatpump (shown as black square): AquaCal SQ120R with pressure bypass and manual bypass
Gas Heater (shown as white square): Pentair MasterTemp with manual bypass. As the temp drops below 50f for a few months overnight we'd like to use gas as a backup in the worst weather.
SWG: IC40

Intakes:
• 2x Hayward skimmers with equalization lines to wall mounted drains each with 2" to the pump
• Floor drain from Spa with a 2.5" line to the pump.

Returns:
• 4x 1.5" return jets in main swimming pool in a 2" loop supplied with a 2.5" pipe from the pump
• 6x Venturi jets (Hayward SP14343PAKA) with a 1.5" loop supplied with a 2.5" pipe from the pump

Jet System
Pump: Pentair Intelliflo 3HP (max 160 GPM) with 3" intake and output pipe.

Intakes:
• 2x Floor drain from Spa with a 3" line to the pump.

Returns:
• 6x Venturi jets (Hayward SP14343PAKA) with a 1.5" loop supplied with a 2.5" pipe from the pump

Air Blower System
Air Blower: Air Supply of the Future Silencer Air Blower, 1.5HP

Measure maximum height of water above lowest section of air channel = 2’ 10” or 34”
For each 10 feet of 2" supply pipe, add 1" (inch) of water pressure = 21’ 6” = 4.25”
For each 90 degree turn, add 1/2" (inch) of water pressure = 11 = 5.5”

Total water pressure = 43.75” = 1.5HP blower

Returns:
• 12x Venturi jets (Hayward SP14343PAKA) with a 1" loop supplied with a 2" pipe from the air blower.

Equipment List

Type	Model	Quantity
Fiberglass Pool	14x34x6 feet	1
Fiberglass Spa	7x9x3 feet	1

Control System	IntelliCenter® with Salt Generator + 8 relays + 2 Actuators	1

Heat Pump	AquaCal SQ120R	1
Heat Pump Bypass	STK0135	1
Gas Heater	Pentair MasterTemp	1
Salt Water Generator	Pentair IC40 (included with IntelliCenter)	1
Cartridge Filter	CJ-2750 Cartridge Filter (potentially different to have a 2.5")	1
Water Pump	Pentair SuperFlo	1
Spa Pump	Pentair IntelliFlo3 Variable Speed and Flow Pump 011075
Air Blower	Air Supply of the Future Silencer Air Blower, 1.5HP	1

Lighting	Pentair Microbrite Color LED 4 Light Combo Kit With Transformer 12V 300W 100' Cord, 602133	1
	Pentair Microbrite Color LED with 100' Cord 620425	1

Three Way Valves	Jandy 4717	4
Two Way Valves	Jandy 4716	2
Check Valves	Jandy 7305	2
Air Blower Check Valve	Air Supply Silencer Check Valve 1/4 lb (included free)	1

Skimmer	Hayward SP1084	2
Skimmer Float Valve	SP1082FV	2
Skimmer Equalization Valve	SP1078	2
Skimmer Eq. Drain	WG1049AVPAK2 (includes 2)	1

Spa Drain	WG1049AVPAK2 (includes 2)	2
Spa Jet Assembly	SP14343PAKA	12
Spa Jet Fitting Tool	SP1434T	1
Whirlpool Jet	SP1437	2
Pulsing Jet	SP1436PAKB	10

Wall fittings	1.5" Hayward SP1023S, (4 returns, 5 lights)	9
Vacuum	W3PVS20JST	1

Skimmer Enclosure	12" Hide Tiles	2
Waterline Tiles	6" x 12" x 100' Tile
Waterline Tile Adhesive	Silicon Rubber Adhesive
Waterline Tile Grout	Silicon Rubber Grout
Solar Cover		1
Pool Rail		1

Questions

1. Would you recommend to use 1.5" for air instead of the 1"?
2. Does the two loops for the different pump returns make sense? I'm particularly concerned about the jet system going from 3" to a 1.5" flow through the manifolds.
3. Will it require a check valve on the spa return for the 6" height difference?

kimkats · Nov 9, 2024

I would be working on the building before I even started the pool. You will need a good venting system as well as a way to remove the humidity from the building.

You also need to plan for how you are going to add/remove water from the pool with it being inside a building.

mareas · Nov 9, 2024

Thanks! The buildings designed and not as a worry. It’s got AC, dehumidifier and EHR with HVAC pro on calculations. Blower door tests etc. I’ll probably install a three way valve between the pump and filter for removing water. A water point close to the pool for cleaning and filling.

ajw22 · Nov 9, 2024

Get an Intelliflo3 pump and not a Superflo pump for the pool.

Superflow pump has 2” in and out, not 3”.

ajw22 · Nov 9, 2024

Put in an automatic bypass controlled by the IntelliCenter for the gas heater.

Pentair has the AUTOMATIC BY-PASS VALVE KIT (P/N 462048) FOR MASTERTEMP® AND MAX-E-THERM® POOL AND SPA HEATERS

Pentair MasterTemp Heaters - Further Reading

www.troublefreepool.com

ajw22 · Nov 9, 2024

Get 011077 Intelliflo3 pumps with the control panel. It will make it easier to manually control the pumps when at the equipment pad.

mareas · Nov 10, 2024

Thanks, that helps a lot! I wasn't sure if the superflo would be ok for the circ pump on a larger tube size but I guess it can impact self priming?

~~1. Would you recommend to use 1.5" for air instead of the 1"?~~
I'd overlooked in the Air Supply manual it recommends 1.5" for the jet so I can make that change.

2. Does the two loops for the different pump returns make sense? I'm particularly concerned about the jet system going from 3" to a 1.5" flow through the manifolds.

I've done some calculations here and the PSI seems well below the acceptable ratings. My only concern is head loss with 3" splitting into two 1.5". I could potentially split them into two loops with a 3" to two 2.5" connections that both connect to two 1.5" for each loop. Will it really sustain more flow or am I being pedantic though?

The dynamic pressure in the 3" pipe with 160GPM is approximately 11.41 PSI.
The dynamic pressure in each 1.5" pipe is approximately 45.69 PSI.

3. Will it require a check valve on the spa return for the 6" height difference?

Still trying to understand this.

ajw22 · Nov 10, 2024

The Superflo VST pump would have worked okay but the Intelliflo3 will give you more flexibility with flow rates and work better.

On the spa jets you need to reduce the 3" feed pipe down to eventually nozzle size.

What air/water manifold will be used at each jet and what size pipe does the manifold take?

You should always have a CV in the spa return of a raised spa to prevent draining back to the pool when the pump is off.

mareas · Nov 10, 2024

They Jet manifold is Hayward SP1434PAKA with 1.5" water and 1.5" air which is looped with six jets on the jet pump. The return for the circulation pump also has six jets which I could put some onto this loop or create a second loop that so the 3" isn't going directly to 1.5"

If I have low floor jets would the same apply for the pipes which feed the jets?

ajw22 · Nov 10, 2024

mareas said:
They Jet manifold is Hayward SP1434PAKA with 1.5" water and 1.5" air which is looped with six jets on the jet pump.

That is fine.

mareas said:
The return for the circulation pump also has six jets which I could put some onto this loop or create a second loop that so the 3" isn't going directly to 1.5"

You jumped from talking about the spa to the pool?

What do you need six returns in the pool?

mareas said:
If I have low floor jets would the same apply for the pipes which feed the jets?

I think we need to see some plumbing diagrams to see what you are describing.

mareas · Nov 10, 2024

Yes think I confused you there. For the circ system the pool has four returns and the spa has six jets. I've put it on a diagram to show more clearly.

ajw22 · Nov 10, 2024

mareas said:
Yes think I confused you there. For the circ system the pool has four returns and the spa has six jets. I've put it on a diagram to show more clearly.

Your diagram looks fine to me. Let's have @mas985 have a look.

mas985 · Nov 10, 2024

mareas said:
1. Would you recommend to use 1.5" for air instead of the 1"?

I would use a 2.5" air line to the spa and then you can step down to the 1.5" lines when you split it for the two half loops around the spa. I am not a big fan of those fittings because they force you to use smaller pipe for the loop. My spa has 6 jets and there is 2.5" around the loop for water and 2" for the air.

Is the spa and fiberglass or a metal spa?

Have you chosen an insert for the manifold?

For 6 jets, 2.5" is minimum for the lines to/from the pump but I would go with 3" for both return and suction water lines and 2.5" for the air line from the pump. Also, you want to make sure a Hartford loop is installed close to the spa.

Will the venturi air line have a slope upwards or downwards from the spa to the equipment?

mareas said:
2. Does the two loops for the different pump returns make sense? I'm particularly concerned about the jet system going from 3" to a 1.5" flow through the manifolds.

Absolutely. That is how my pool/spa is plumbed. Using the same pump for the circulation and the spa jets is not a great option because it forces high flow rate water through the filter and heater which makes the jets not as strong.

mareas said:
3. Will it require a check valve on the spa return for the 6" height difference?

Yes

mareas said:
They Jet manifold is Hayward SP1434PAKA with 1.5" water and 1.5" air which is looped with six jets on the jet pump. The return for the circulation pump also has six jets which I could put some onto this loop or create a second loop that so the 3" isn't going directly to 1.5"

From the pics, it looks like there are only 4 lower venturi jets on the main pump which would make sense if you are running these off the main pump which has to go through the filter and heater so there is less flow rate.

Also, from the pics, it looks like there is only 1 MD for the suction line of the main pump. This is not to code. There should be a split MD for that pump as well.

mareas said:
If I have low floor jets would the same apply for the pipes which feed the jets?

If they are same venturi jets, then the plumbing is identical. However, if there are only 4 lower jets, then 2.5" to/from the spa for those is fine.

mareas · Nov 10, 2024

Is the spa and fiberglass or a metal spa?

They are both fiberglass and should be "normal" as they are locally produced for export to USA.

For 6 jets, 2.5" is minimum for the lines to/from the pump but I would go with 3" for both return and suction water lines and 2.5" for the air line from the pump. Also, you want to make sure a Hartford loop is installed close to the spa.

Not disagreeing with your experience here but they specifically state 2" going into 1.5" for the jets on the 1.5HP Air Supply Silencer. Would you recommend an alternative model that recommends 2.5"?

Have you chosen an insert for the manifold?

I'm thinking of the whirlpool (SP1437) and pulsing jet (SP1436PAKB). The best brochure I've found with information is available here. It looks like the minimum is 10 GPM but I've not been able to find nozzle sizes and higher limits.

Also, from the pics, it looks like there is only 1 MD for the suction line of the main pump. This is not to code. There should be a split MD for that pump as well.

Thanks, I was having trouble fitting four in the floor of the spa with a 3' distance between each but I'll move the light somewhere else. I have seen the new hayward sump drains but do you know if there are any unblockable drain choices for fiberglass pools?

From the pics, it looks like there are only 4 lower venturi jets on the main pump which would make sense if you are running these off the main pump which has to go through the filter and heater so there is less flow rate.

There is actually six (12 in total) but perhaps it would be better to separate them further for the different nozzles and to increase flow in those jet assemblies:

Jet pump: outputs to 8x pulsing jets at average of 160GPM or (20GPM per jet). I can split these 8 into two loops of 4 on the 1.5" tubing which would slightly improve
Circulation pump: outputs 4x whirpool jets acting as floor bubblers to max of 30GPM. I'd need to calculate the power loss through the equipment for the Intelliflo 3HP but the 2.5" piping would support up to 120GPM for this.

mas985 · Nov 10, 2024

mareas said:
They are both fiberglass and should be "normal" as they are locally produced for export to USA.

Yes, they are one type of "normal" spa jets just not the manifolds that I would choose. But given the spa is fiberglass, you are limited in what you can use. One way to get around the limitation is to split the return pipe in half and then half again so each branch is feeding only two jets. That way you are not trying to feed to many jets off of a single 1.5" line. That can cause jet flow imbalance leading to unequal jet performance.

mareas said:
Not disagreeing with your experience here but they specifically state 2" going into 1.5" for the jets on the 1.5HP Air Supply Silencer. Would you recommend an alternative model that recommends 2.5"?

They are specifying a minimum diameter for the air line. The connection does not need to be the same size as the air line since a bushing can be used to connect the two different sizes.

However, I would recommend a spa jet system without a blower. They are loud and use lots of energy and it is not hard to design a system without one. I don't have a blower on my spa and get plenty of bubbles without one. The key is to use large water lines and large air lines as well as a Hartford loop. Most PBs recommend blowers because they really don't know how to design a spa without one. Most don't have a background in hydraulics.

How close is the equipment to the spa? Again, is there a slope change?

mareas said:
I'm thinking of the whirlpool (SP1437) and pulsing jet (SP1436PAKB). The best brochure I've found with information is available here. It looks like the minimum is 10 GPM but I've not been able to find nozzle sizes and higher limits

The higher the flow rate, the more the pipe size and air line size will make a difference.

mareas said:
.Thanks, I was having trouble fitting four in the floor of the spa with a 3' distance between each but I'll move the light somewhere else. I have seen the new hayward sump drains but do you know if there are any unblockable drain choices for fiberglass pools?

Would this fit:

AquaStar Light Gray 32" Channel Drain with 3 Port PVC Sump, AV Anti-entrapment Suction Outlet Cover, VGB Series, 32CDAV103

AquaStar Light Gray 32" Channel Drain with 3 Port PVC Sump, AV Anti-entrapment Suction Outlet Cover, VGB Series, 32CDAV103 (API-25-1291), 883612014869

www.eztestpools.com

Another option is to use wall mounted MDs.

mareas said:
There is actually six (12 in total) but perhaps it would be better to separate them further for the different nozzles and to increase flow in those jet assemblies:

Jet pump: outputs to 8x pulsing jets at average of 160GPM or (20GPM per jet).

So 4 jets on the main pump and 8 jets on the jet pump?

I don't think you will get 160 GPM on the jet pump with that configuration (see below).

mareas said:
Circulation pump: outputs 4x whirpool jets acting as floor bubblers to max of 30GPM. I'd need to calculate the power loss through the equipment for the Intelliflo 3HP but the 2.5" piping would support up to 120GPM for this.

I don't think you will get 120 GPM when going through a filter and heater. There is head loss in not only pipe, fittings & valves but also in the filter and heater and not to mention the jets which are very high in head loss.

I put together a head loss model to show you approximately how much flow rate you could expect out each loop.

Pool Pump Tools v030 - mareas

docs.google.com

The loop with 4 spa jets going through the filter and heater, the pump would likely get about 68.6 GPM or 17.2 GPM/jet.

For the spa jet pump with 8 jets, you will get about 130.9 GPM or about 16.4 GPM/jet.

If you upgrade spa jet pump to an Intelliflo XF, you can expect about 141.3 GPM or 17.7 GPM/jet.

mareas · Nov 10, 2024

Yes, they are one type of "normal" spa jets just not the manifolds that I would choose. But given the spa is fiberglass, you are limited in what you can use. One way to get around the limitation is to split the return pipe in half and then half again so each branch is feeding only two jets. That way you are not trying to feed to many jets off of a single 1.5" line. That can cause jet flow imbalance leading to unequal jet performance.

I'm with you, I meant it to be read as a standard fiberglass pool and not below a common standard outside the US. Understand the point though and I'm not fixed on the manifold they are just often recommended with the fiberglass pools and hard to find alternatives. CMP might have a system where I can use a venturi tee (CMP 23306-100-000) into a 1.5" FIP x 1.5" Socket return fitting (25522-100-000) with a 1.5" FIP therapy jet (1.5" Therapy Jet Internals - CMP). It might increase the air flow? Would you recommend them as a reliable brand though? I've heard they were recently bought out and some lines are not going to be produced anymore so I was trying to align closer with the larger brands.

There is a guide here but not much useful figures: https://www.c-m-p.com/wp-content/uploads/2014/03/10000-300-247-Spamaster-1-5-Deluxe-Jet-SCREEN.pdf

How close is the equipment to the spa? Again, is there a slope change?

20 feet and no significant change. That's for the mechanical room but I could easily build an equipment pad within a few feet if necessary.

Would this fit?

Unfortunately not. I really like them but they are all for gunnite pools. I'll try use a mix of wall and floor but four 8" drains in a small spa seems tight.

So 4 jets on the main pump and 8 jets on the jet pump?

That's correct but not final if you recommend otherwise. I've also considered two bubblers in the spa instead of the four pumps but would that require a blower?

The loop with 4 spa jets going through the filter and heater, the pump would likely get about 68.6 GPM or 17.2 GPM/jet.

For the spa jet pump with 8 jets, you will get about 130.9 GPM or about 16.4 GPM/jet.

Thanks for those! I was hoping someone would help me with the spreadsheet later but this is really helpful.

mas985 · Nov 11, 2024

mareas said:
I'm with you, I meant it to be read as a standard fiberglass pool and not below a common standard outside the US. Understand the point though and I'm not fixed on the manifold they are just often recommended with the fiberglass pools and hard to find alternatives. CMP might have a system where I can use a venturi tee (CMP 23306-100-000) into a 1.5" FIP x 1.5" Socket return fitting (25522-100-000) with a 1.5" FIP therapy jet (1.5" Therapy Jet Internals - CMP).

That might work.

The exterior fittings only change how the jet moves. I like the spinners:

mareas said:
It might increase the air flow?

It might help with both air and water flow.

mareas said:
20 feet and no significant change. That's for the mechanical room but I could easily build an equipment pad within a few feet if necessary.

20 feet is fine.

mareas said:
Unfortunately not. I really like them but they are all for gunnite pools. I'll try use a mix of wall and floor but four 8" drains in a small spa seems tight.

That may be the best approach.

mareas said:
That's correct but not final if you recommend otherwise. I've also considered two bubblers in the spa instead of the four pumps but would that require a blower?

Yes, bubblers do require a blower because they do not have a venturi.

mareas said:
Thanks for those! I was hoping someone would help me with the spreadsheet later but this is really helpful.

I modified it for the 20' lengths although it does not change much for just pipe length.

mareas · Nov 11, 2024

I've called around today which helped conclude a few points:

No venturi tees designed for fiberglass installs
At least for the popular brands which only use jet manifolds/bodies. The hayward might be a better alternative if this is the case as they have the 1.5" line rather than a 1" line for air. Internally in the bodies though I believe they both narrow to around 1/2" to 3/4" entry though but hard to get exact measurements from their support on this.

The 1.5" CMP jets aren't adjustable but the 2.5" spa jets would be.
The jet's linked above are also not able to be adjusted (water/air mix) and they recommend their 2.5" range (2.5" Spa Master™ Jets - CMP) for that purpose. If the flow is imperfect across the jets they can at least be adjusted.

There is a strip drain for fiberglass pools
Waterway provide the following unblockable strip drain with https://waterwayplastics.com/wp-content/uploads/807-0240.0410_reduced.pdf which is a huge improvement on four circle sump drains!

Based on your feedback I've made adjustments to align on your proposed method (I've not completed air lines yet). In the design:

3" jet pump return line is reduce to two 2.5" lines
Each 2.5" line is reduced into two 2" lines
Each 2" line is split into two 1.5" line to feed a single jet body/manifold.

The circulation system:

2.5" circ pump return line is reduce into two 2" lines
Each 2" line is split into two 1.5" lines to feed a single jet body/manifold.

It obviously looks far less elegant but having each jet on its own 1.5" line does make sense if that looks right to you?

I was also wondering if there is any good information on designing the venturi system without a blower? Is it virtually the same as with a blower but with a hartfood loop near the spa or is it worth separating the jets into sets to have an air adjustment valve?

mas985 · Tuesday at 10:31 AM

mareas said:
No venturi tees designed for fiberglass installs
At least for the popular brands which only use jet manifolds/bodies. The hayward might be a better alternative if this is the case as they have the 1.5" line rather than a 1" line for air. Internally in the bodies though I believe they both narrow to around 1/2" to 3/4" entry though but hard to get exact measurements from their support on this.

What matters more is how these are fed. Using the binary tree I outlined above will help prevent excess losses.

mareas said:
The 1.5" CMP jets aren't adjustable but the 2.5" spa jets would be.
The jet's linked above are also not able to be adjusted (water/air mix) and they recommend their 2.5" range (2.5" Spa Master™ Jets - CMP) for that purpose. If the flow is imperfect across the jets they can at least be adjusted.

There is a strip drain for fiberglass pools
Waterway provide the following unblockable strip drain with https://waterwayplastics.com/wp-content/uploads/807-0240.0410_reduced.pdf which is a huge improvement on four circle sump drains!

Based on your feedback I've made adjustments to align on your proposed method (I've not completed air lines yet). In the design:

3" jet pump return line is reduce to two 2.5" lines

Each 2.5" line is reduced into two 2" lines

Each 2" line is split into two 1.5" line to feed a single jet body/manifold.

The circulation system:

2.5" circ pump return line is reduce into two 2" lines

Each 2" line is split into two 1.5" lines to feed a single jet body/manifold.

It obviously looks far less elegant but having each jet on its own 1.5" line does make sense if that looks right to you?

These layouts should work fine. The last TEE before the jet body can be done between two jet bodies to simplify the layout and eliminate the need for additional fittings.

mareas said:
I was also wondering if there is any good information on designing the venturi system without a blower? Is it virtually the same as with a blower but with a hartfood loop near the spa or is it worth separating the jets into sets to have an air adjustment valve?

When a blower is used for a venturi jet, in most cases it is used to help clear the air line of water. Most PBs do not use a Hartford loop at the spa so what happens is when the jet pump is shut off the entire length of the air pipe fills with water and then when the pump turns on, it is too much water to clear. So instead of designing the air line so it does not fill with water, the PB uses a blower instead to help clear the lines. But the problem that I have seen on this forum is that the blower ends up adding too much air to the air lines and the bubbles tend to blow water up on the deck.

For the design of a spa without a blower and with long air lines, it is the Hartford loop that is key. However, if the outlet of the airline is within about 15' of the spa or the air line slopes upward away from the spa, then in most cases, even a Hartford loop is not necessary. The point is to prevent a long and deep section of the air line from filling with water.

However, if you want air adjustments for the air line, then I would put in a spa side valve for each spa jet so everyone can have there own air line adjustment. In this case, no Hartford loop is necessary and the air line loop around the spa goes away. The air lines for each jet simply go upwards to the deck where a twist valve allows adjustment for the jet air. This is very similar to how standalone spas handle air adjustment. There are many different styles for this but here are a few examples:

spa side venturi air line valve - Google Shopping

www.google.com

The type you use will depend on exactly where it is located.

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