IG Spa jets: low flow/no air, new (re)build

[KellyAH]

I've read quite a lot here on plumbing and pipes and old posts about no bubbles in spa jets, but since we have a new pool (well, old pool, but all new piping), I feel like our problems are because our pool builder didn't design it properly. I'd love your perspective.

Problem: Spa jets have weak flow and no bubbles.

Equipment: Hayward SwimClear C4030 filter, 2.7HP Hayward pump/motor, Jandy heater with diverter

Design: See photos. 30-foot air pipe from pool equipment to the spa. Air can be force-blown into the pipe (no blockage). There's no blower (but because the spa isn't working, the builder says he'll comp a blower, but that won't fix the weak jets). The water return pipes have some sort of reducer inside the pipe (need some extension tool they used to remove them).
We previously had 3 jets (each with two openings, top/bottom) and when we ran with a 1.5HP pump, the jets (max flow) would spray across the spa pretty hard. We specifically asked for two extra jets (never mind that they did a really stupid design and just put the jets between the other three, leaving a seat gap without a jet--first clue of bad design?)
Now (see photos), on max flow with a 2.7HP Hayward pump/motor, the jets barely pump out. We wondered what would change if we plugged some of the jets (with our fingers), and what happened is that water ran up through the air pipe and spilled out at the opening (by the pool equipment).

The pool has three returns that have high flow/pressure (gaging just by feel), whereas in the spa, the jets are all weak.

Can this be fixed? I have very little confidence now that we hired a professional (lots of other things wrong but this is a major issue).
Thank you!


Weak spa jets. This is 100% max flow:



Pool equipment (and yes, for all new install, I'm well aware now of the bad design, many bends, etc); air pipe is 3rd from right front:



Two rows of jets supplied by one return line (middle, 90° bend):



Air line goes up and over then reduces
(at least this is my best guess--I'm no expert). Second image is labeled:



Narrow pipes tied in to water jets/return but not yet connected to the air inlet shown above:

 

[ajw22]

I count 9 jets in your spa pic. For decent pressure each jet needs 10-20 gpm of water flow. That means you need 90 - 180 gpm of water flow. To get that you need a dedicated spa jet pump not running through a filter or heater with 3" pipes. You don't have that.

At best with your setup you can get maybe 80 gpm which gives you 8 gpm for each jet.

If your spa plumbing is all closed in it is going to be difficult to change things now.

Your air system is a whole other problem but of little consequence until you have a plan to fix your spa jet flow.

 

[KellyAH]

I count 9 jets in your spa pic. For decent pressure each jet needs 10-20 gpm of water flow. That means you need 90 - 180 gpm of water flow. To get that you need a dedicated spa jet pump not running through a filter or heater with 3" pipes. You don't have that.

At best with your setup you can get maybe 80 gpm which gives you 8 gpm for each jet.

If your spa plumbing is all closed in it is going to be difficult to change things now.

Your air system is a whole other problem but of little consequence until you have a plan to fix your spa jet flow.

Thank you for that. We did a 5gal/bucket test, filled in 34 sec, so about 8.9gpm per jet. There are 10 jets, so 89gpm water flow.

I just read the user manual for the VS pump and it says we need a minimum of 12.5 inches of straight pipe run going into the pump, but we have only 4. I remarked that they didn't install the equipment correctly and now I have concrete evidence to that effect. Sigh.

The filter has a max flow of 150gpm, so I'm wondering if the "easy" fix is a much higher capacity pump (costing me in electricity) or to move all of the installed equipment so that the pump actually gets the correct inlet install. It seems like if it's correctly installed per the manual, it would still only get 110gpm, or about 11gpm per jet, which is above the minimum you listed, but that doesn't seem optimal at all.

 

[ajw22]

90 GPM is about the max you can expect to push through your equipment. Your filter is not the limiting factor. A bigger pump will not give you much more flow.

You need more like 150 gpm to 180 gpm to be happy. That takes a dedicated pump running through 3” pipe without restrictions of a filter or heater.

 

[KellyAH]

90 GPM is about the max you can expect to push through your equipment. Your filter is not the limiting factor. A bigger pump will not give you much more flow.

You need more like 150 gpm to 180 gpm to be happy. That takes a dedicated pump running through 3” pipe without restrictions of a filter or heater.

It sounds to me like my PB "designed" something that will never work. At 90gpm, needing 15gpm per jet, we can only have 6 jets, which is what the old spa had (and worked fine) but we had specifically (per contract) asked (and paid) for extra jets.

I also read the pump manual, which specified a straight line "L" distance of at least 12.5 inches, but we don't even have one inch.


What if a few of the jets were plugged? We tried that with our fingers, and then water just backed up and spilled through the air line.

Thank you so much for your help here.

 

[ajw22]

It sounds to me like my PB "designed" something that will never work. At 90gpm, needing 15gpm per jet, we can only have 6 jets, which is what the old spa had (and worked fine) but we had specifically (per contract) asked (and paid) for extra jets.

Your builder must have slept through Hydraulics 101 class.

Hydraulics 101 - Have you lost your head?

Edit - Before reading this article, you may want to first familiarize yourself with this Pool School article on Pump Basics Hydraulics 101 - Pump Head Curves, Plumbing Head Curves and Operating Points Hydraulic Head In fluid dynamics, head is a concept that relates the energy in an...

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I also read the pump manual, which specified a straight line "L" distance of at least 12.5 inches, but we don't even have one inch.
View attachment 354420

That is not optimum and can effect pump priming.

What if a few of the jets were plugged? We tried that with our fingers, and then water just backed up and spilled through the air line.

I believe your old setup did not have air ports.

Your builder did not use the type of air/water manifold used in new builds. He hacked something together that does not work very well.

 

[KellyAH]

Thanks for your help. I'm about to cry because it seems more clear that the PB did such a bad job that there is no solution here other than tearing it all up and redoing it.

I guess maybe now we need to hire a **real expert** to come and review the system to see what needs to be done.

 

[mas985]

Don't feel too bad. This is a very common problem with PBs.

The easiest and least expensive fix is to plug a few of the jets. I am assuming when you tried to plug the jet, you plugged the outer fitting. That won't work. You need to actually plug the jet nozzle orifice. This requires removing the jet and putting in a plug (I have used hot glue before and that seems to work ok). Given your setup, I would not run more than 6 jets. If it were me, I would plug all the bottom jets as those look to be very low so will not be all that comfortable if you know what I mean.

But first, do you know what kind of jets the PB installed?

Are the external fittings shown in the picture above and insert or just an eyeball?

Did the jets look like the pic Allen posted?

 

[KellyAH]

Don't feel too bad. This is a very common problem with PBs.

The easiest and least expensive fix is to plug a few of the jets. I am assuming when you tried to plug the jet, you plugged the outer fitting. That won't work. You need to actually plug the jet nozzle orifice. This requires removing the jet and putting in a plug (I have used hot glue before and that seems to work ok). Given your setup, I would not run more than 6 jets. If it were me, I would plug all the bottom jets as those look to be very low so will not be all that comfortable if you know what I mean.

But first, do you know what kind of jets the PB installed?

Are the external fittings shown in the picture above and insert or just an eyeball?

Did the jets look like the pic Allen posted?

Thanks for the reply!

I don't know the type of venturi, but when they came over the first time to try to fix it, they had an extension tool with a socket wrench to unscrew the piece to make sure they weren't plugged. My husband says they looked sort of like this:



The part where the water comes out at the spa wall (external fitting) is just an eyeball that you can rotate a bit. When we tried to plug them, you're right that we just plugged (with our fingers) the eyeballs and then water backed up and went out the air vent by the pool equipment.

Thanks for the reply!

 

[mas985]

Yes that is the jet nozzle. You might be able to find one with a smaller hole. Those require less flow per jet so they would work better.

If not then the next solution would be to halve the number of jets. You can do that by turning that piece upside down and filling it with hot glue or something else that can be removed easily if you change your mind. Then reinstall the jet. That blocks the water flow without forcing it into the air line.