No water pressure in spa return

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Hello , I tried to figure out for several months now why I’m not getting good pressure in my spa jets.
Background: I have a shared pool/spa (concrete) I fired my builder because he was a scammer , long story short i has to continue the project by myself and hire subs up to the end of the project.

It was too late to replace the plumbing with 2” pipes , the builder starts with 1.5” but I didn’t know until the deck was poured.

The spa was built by another pool builder , no one is taking responsibility for anything because I didn’t hired them from the beginning.

I was able to change the return line to the spa with 2” as well as the air blower.
The main drain for the spa still 1.5”
The distance between the spa and the equipment is 100’

When I run the pump in pool mode/spillway I feel good pressure on all 3 jets in the pool but I don’t feel good pressure in the spa
When I’m on spa mode I must run the pump on 3100+ to feel little bit of pressure .
Every time I use the spa I need to turn on the blower so I can virtually feel any movement .

I was told “ this is normal but it’s not. I still need to feel good pressure of water inside the spa without running the air blower.

I was told my filer is too small , it’s 24” , i tried to bypass the filter using the 6 way valve , I can feel better pressure but not as it should be .

I was told if I get a bigger sand filter or cartridge filter it will have better back pressure and I will gain more pressure in the spa .

I really appreciate if anyone have any comment on this , I’m loosing my mind over this .

The eyeballs are 1” and I can’t get a smaller ones because the builder said it has to be self aligned type , not sure what’s that .

Attached a drawing of spa plumbing
Thank you in advance
 

Attachments

  • 3A7AAF7A-5483-4BA3-BA5F-033CF165EE4C.png
    3A7AAF7A-5483-4BA3-BA5F-033CF165EE4C.png
    668.3 KB · Views: 15

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
15,053
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
I was able to change the return line to the spa with 2” as well as the air blower.
The main drain for the spa still 1.5”
The distance between the spa and the equipment is 100’
With 6 jets, you really should have a minimum of 2.5" plumbing. Also, the filter and heater usually requires a bypass. 1.5" suction line is a serious issue. You may not be able to overcome that restriction.

If you can replace the jet nozzles with 1/4" jets, that may help a little. The nozzle is deep within the spa wall and is removed with a long socket wrench. The external eyeballs do not really matter much.

Jet%20Nozzle.jpg

1637339449569.png
 
Last edited:

vtpools

In The Industry
Apr 26, 2019
83
VT
Biggest issue is that 1.5" suction line. It's possible to make a bit of a manifold by plumbing the spa and pool into a 2" tee if that makes sense, that'll give you the most on the suction end you can get. 2" tee with bushings down to 1.5" for the spa and pool suction lines, then 2" straight into the filtration system. It defeats the purpose of being able to run the spa separately but will give you more water flow than you are getting currently. Honestly though you really need the larger lines to get the result you're looking for. Cartridge filter will help. The run is also very long. Is the blower connected straight into the spa return line or is there a separate air line and venturi style spa jets?
 

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Biggest issue is that 1.5" suction line. It's possible to make a bit of a manifold by plumbing the spa and pool into a 2" tee if that makes sense, that'll give you the most on the suction end you can get. 2" tee with bushings down to 1.5" for the spa and pool suction lines, then 2" straight into the filtration system. It defeats the purpose of being able to run the spa separately but will give you more water flow than you are getting currently. Honestly though you really need the larger lines to get the result you're looking for. Cartridge filter will help. The run is also very long. Is the blower connected straight into the spa return line or is there a separate air line and venturi style spa jets?
Thank you for your reply , the airline is connected to the blower on separate line , is it’s Venturi jets .
 

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
With 6 jets, you really should have a minimum of 2.5" plumbing. Also, the filter and heater usually requires a bypass. 1.5" suction line is a serious issue. You may not be able to overcome that restriction.

If you can replace the jet nozzles with 1/4" jets, that may help a little. The nozzle is deep within the spa wall and is removed with a long socket wrench. The external eyeballs do not really matter much.

Jet%20Nozzle.jpg

View attachment 382657
Thank you , I was looking on your drawing and I don’t think I have a bypass like that , so the bypass basicly split the water pressure ? Thanks
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
15,053
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
I believe the issue that you are having is that the flow rate that the pump is delivering is too low for the jets you have. Jets with larger nozzles require more flow rate. Jets with smaller nozzles require less flow rate.

Also, the plumbing design has a major impact on flow rates. Small pipe, filters and heaters all reduce flow rate. The bypass, allows water to travel a different path that has less head loss than the path through the filter and heater. This reduction in head loss helps to increase the flow rate through the jets.

The combination of the bypass and smaller jets will improve the strength of the jet. However, you may also need to plug some of the jets to get to full strength. 1.5" pipe has a lot of head loss and cannot support high flow rates that 6 spa jets require so you may need to go down to 4 jets. These are the changes I would make one at time and see if the jets become strong enough for your liking:

1) Replace jet nozzle with 1/4" nozzle
2) Install filter/heater bypass as shown in the picture above
3) Plug two jets - this require removal of the nozzle and either replace it with a plug or fill the nozzle with hot glue or something else to create a plug and reinstall.

What is the pump make/model?
 
Last edited:

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Thank you very much I really appreciate your comment , also maybe you know what I need to do in winter .
I do not winterize the pool bc I use the shared spa and the spillway , so pretty much everything is running just like in the summer time .

Today the temperature dropped to 32 and the auto freeze mode start both pumps , one tor the water features and one for the pool/spa , however it's running on a pool mode so as my understanding the pool MD , pool returns and spa jets along with both skimmers running now under the freez mode , I wonder what do I need to do in order to avoid damages to the spa main drain because no water flow, the main drain in the spa only opens when the system is on spa mode.
Should i manually (on the app) set the system in spa mode for few minutes just to let the water run through the spa main drain as well ?

Thanks
 

Enjoying this content?

Support TFP with a donation.

Give Support

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
I believe the issue that you are having is that the flow rate that the pump is delivering is too low for the jets you have. Jets with larger nozzles require more flow rate. Jets with smaller nozzles require less flow rate.

Also, the plumbing design has a major impact on flow rates. Small pipe, filters and heaters all reduce flow rate. The bypass, allows water to travel a different path that has less head loss than the path through the filter and heater. This reduction in head loss helps to increase the flow rate through the jets.

The combination of the bypass and smaller jets will improve the strength of the jet. However, you may also need to plug some of the jets to get to full strength. 1.5" pipe has a lot of head loss and cannot support high flow rates that 6 spa jets require so you may need to go down to 4 jets. These are the changes I would make one at time and see if the jets become strong enough for your liking:

1) Replace jet nozzle with 1/4" nozzle
2) Install filter/heater bypass as shown in the picture above
3) Plug two jets - this require removal of the nozzle and either replace it with a plug or fill the nozzle with hot glue or something else to create a plug and reinstall.

What is the pump make/model?
I was thinking about booster pump what you think ?
Thanks
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
15,053
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
I was thinking about booster pump what you think ?
Thanks
I don't think that would be a good idea with 1.5" pipe. The suggestions I gave above would be more effective and safer. The idea is to reduce the flow rate requirement to accommodate the plumbing rather than trying to force more flow rate through highly restrictive plumbing.


1) Replace jet nozzle with 1/4" nozzle
2) Install filter/heater bypass as shown in the picture above
3) Plug two jets - this require removal of the nozzle and either replace it with a plug or fill the nozzle with hot glue or something else to create a plug and reinstall.

What is the pump make/model?
Again, what is the current pump make/model?
 

Ti3155

Well-known member
Jan 9, 2021
135
Myrtle Beach, SC
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
One more thing I forgot to mention.
I have an extra 1 5" pipe close by the main drain , this pipe is not in use , the pb never used it and still underground, I know the exact location of this pipe start to end .

I want to ask if for an example I will install a T in the spa main drain (x2 , 1.5" pipes all the way to the pad from the spa)
Then I will T at the pump .
Am I going to get a better suction from that so maybe I'll have a better flow on the spa return .

Here's my idea ..
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
15,053
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
Pentair vsf ,
The jets are 2" not 1.5"
The only 1.5" currently is the main drain (spa) Thanks
That is even worse and could cause cavitation in the pump.

Adding a second line on the suction will definitely help but may still not be enough. 100' of 2x1.5" and 2" line is still quite a bit of head loss.

Why the resistance to changing out the jet nozzles? It is the cheapest and most effective at increasing spa jet performance.

Do you know what size nozzle is installed right now?

BTW, I don't think I mentioned this before but you can remove the nozzles and flush the lines. Often times during construction, debris gets in the spa lines and you have to remove the nozzles to flush it out.
 
Last edited:
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread