SPA PLUMBING

[shauney]

i start my pool/spa combo next week and i wanted to get some feedback from pool/spa builders. i am contracted for a 7' by 7' integrated octagon spa. the spa will have a dedicated 2.5hp pentair pump on 2.5" pipe on a 25' run. originally my builder was going to place 5 jets on 1 loop but i then wanted 7 jets. he now wants to use a 2 loop system for the 7 jets (3 jets on 1 circuit and 4 jets on a 2nd circuit). he would place a 3-port valve off the pump so that i could controll the flow to one or both circuits. i told him that i wanted a spa that "rocks" (lots of action). he said he has used this system on lots of commercial work and i will not be dissapointed. anybody out there ever plumb a spa this way and how effective is it?

 

[PoolGuyNJ]

Works

 

[shauney]

spa plumbing

thanks pool guy- are you a builder and have you much experience with this design?

 

[shauney]

i just turned my spa on and i am very dissapointed. i have excellent power when i have the 3 jet loop on and also the 4 jet loop. but when i turn on all 7 jets (2 loops) i have almost no power. my builder said i would have a little less power when both circuits are open but this is not usable. anybody have an idea what the fix is for this? i am thinking we need to add another spa booster pump and have 1 pump for the 3 jet loop and 1 pump for the 4 jet loop. appreciate your feedback.

 

[mas985]

Do the spa jets go through the filter and heater?

That may be a limiting factor for your flow rates.

A second pump would definitely help although you really should have enough flow for 7 jets unless they are high flow versions (> 15 GPM each).

 

[Guest]

what if you added a blower insted of another water pump, that would add the neat bubble feel.

 

[shauney]

mas985- the spa has a dedicated booster pump as described above and does not go through the pool filter. i could be wrong but i dont think a blower is going to increase the pressure coming out of the jets.

 

[Guest]

a blower would increase the force of the jets, but with air insted of water, it can be nice and it adds little bubbles to give you an even more spa feeling. you could do a nother pump, but that would be a good bit of modfication to your pluming, a blower i *think* you just hook up to the same pipe of the returns for the spa.

also, since your build is done we need pics :-D

 

[mas985]

mas985- the spa has a dedicated booster pump as described above and does not go through the pool filter. i could be wrong but i dont think a blower is going to increase the pressure coming out of the jets.

Unfortunately, air is not as strong as water. Adding more air will just add more air. If you want stronger jets, you need more water flow.

 

[divnkd101]

Shauney,

Have you gone through the valving sequences with your PB? You mentioned in one of your posts that things are good on 3 jets and 4 jets but when you convert to 7, things go downhill from there. Perhaps in the valving switchover, something is being restricted. Keep us posted.

 

[shauney]

one of the builders was here today and agreed its not acceptable. he says it has to be corrected but he is not sure what the correct fix is. he says there may be a few ways to fix. he mentioned changing out the spa booster pump for a bigger one. there are no obstructions. this is a faulty design problem and i cant live with it. when i turn the valve to have all 7 jets on i get 4 powerful jets and 3 jets that have no force. builder has to talk to his partner who designed this system and then see what we can do. he did say he did not think we had to rip up the spa. i am thinking we need to get more horsepower. all input appreciated.

 

[mas985]

Let's start with some basics.

How much flow (GPM) is required for each jet? Should be in the manufactures specs.

You metioned that when all are on, the 4 jet loop is strong but the 3 jet loop is not. Correct? It really should be the opposite which means the 3 jet loop may have an issue. Is it the same size pipe as the 4 jet loop?

Is there one 3-way valve that controls both loops or separate valves?

Also, is there only one suction line from the spa to the pad? Size?

An option would be to put each loop and a separate pump but if the suction line is not big enough, this could be a problem.

One more thing, what is the pump model?

 

[shauney]

mas985- thanks for the input. i do not know the spa jet gpm. the spa booster is a 2.5hp pentair (i think whisperflo) but i dont know which model. i am not at home right now. if you open the valve for the 3 jet loop you will get powerful flow from that loop and the same when you turn the valve and open the 4 jet loop. however, when you turn the valve to open to both loops (all 7 jets) you will only get good flow to either the 3 jet loop or the 4 jet loop but not both. why doesnt the water flow equally through both loops and then give equal output from each jet?. i am assuming both loops were plumbed with the same size pipe. one 3 way valve controlls both loops. i dont know if this makes sense but i have something labeled spa suction for the pool side and then something labeled spa secondary suction line. on the plans it looks like i have 3" main drain spa suction line. i am getting worried because i have not heard back from my builder and he said he had to talk to his partner to discuss the fix. can we add a second spa booster pump (one for the 3 jet loop and one for the 4 jet loop)? would replacing the current pump with a more powerful one help? appreciate all input.

 

[mas985]

I think one of the problems you are experiencing is that the two loops are imbalanced so they have different flow rates. You want a bit more flow to the 4 jet loop since it has more jets but it sounds like there is too much flow to this loop. This is not uncommon since it is difficult to balance the lines exactly. This is why it is important to have ball valves in each loop so that you can adjust them for proper flow.

One thing to try is to remove all of the jets from the spa, they should screw out, and run the pump to clear out any debris. Check the spa fixtures to make sure they are clear as well. Sometime dirt and rocks get into the lines during construction and they need to be cleared out.

Part of the problem could be different size pipe but you will have to check with the PB to see what he used. Also, you should be able to adjust the flows to make each loop equal with the three way valve. You will have to adjust the valve such that when operating both loops, the stronger loop is partially off. This will redirct more flow to the weaker loop and with fine tuning, you should be able to make them appear equal. At that point you can decide if it is good enough. If not, you will probably need a second pump.

If you like the 2.5 HP, with either 3 or 4 jets, you could duplicate that but that seems like a lot of pump for just 3 jets. I have a 1 HP for 6 jets and they seem fine for me. However, I don't really like them too strong anyway. With 4 jets, a 1.5 HP should be more than enough for each loop but again, it depends on the jets you are using. If you have a 3" suction line from the spa, then that should handle two separate pumps easily.

After making sure the lines are clear, one thing the PB could do is take a pressure measurement at the pressure side drain port of the pump. If it is really high (> 30 PSI), then a higher HP pump may not help much and the problem is with the plumbing. Then we can talk about other options.

 

[Guest]

to me they should have put 8 jets in, 4 and 4, i bet that would help make this easier to balance it.

 

[shauney]

mas985-thanks. so if i understand you, when somebody has 2 loops and they are not in balance the waterflow will come through 1 loop and not both loops equally? thats why i am getting all the pressure coming out of just 4 jets and not all 7? is rollin thunder correct about the 8 jets? also,why would the plumber use different size pipe for the loops? i will try playing with the valve and see if i can get equal flow to both loops. the builder did tell me i would lose some flow when i turned on both loops but i thought the flow would be equal to all 7 jets. if i have enough suction it seems a simple fix would be to add a 1.5hp booster pump to the 3 jet loop and leave the 2.5hp for the 4 jet loop. but can this be done if i dont have 3" suction line? if the pressure side measurements come out high does that mean i can not add power to fix the problem? i will get you the other info you wanted but based on the info you have what do you think is the chance that i will have to rip-up the spa?

 

[JasonLion]

If everything was done correctly the 2.5 HP pump should have been enough. Obstructions in the pipes can set things out of whack, and that is not uncommon with new construction. The pipe might narrow somewhere and that could be restricting the flow. Higher than usual flow rate jets might require a larger pump. There are quite a few possibilities.

It is difficult to say exactly what will happen for any proposed change because there are so many different ways things might be plumbed. If the suction line isn't large enough and you have two pumps the larger pump can starve the smaller pump of water.

Even with 4 and 4 jets on the two loops there is always a possibility of the two loops being unbalanced. One way or another there has to be a way to balance the two loops. I believe you said you had a three way valve, if so you need to adjust it until the two loops are equal. Alternatively, two ball valves, one for each loop, can be used to balance the two loops. This will be true in any case.

 

[shauney]

jasonlion-thanks. i guess there is always the possibility of obstruction/debris in the plumbing but when i turn the valve to the 3 jet loop those 3 jets have good flow and when i turn the valve to the 4 jet loop those other 4 jets have good flow. the loops not being balanced seems like a good possibility but can this be fixed? when i get home i will try to rotate the valve and see if i can get equal flow coming out of all 7 jets. do builders ever place all 7 jets on 1 loop? can these ball valves still be placed to balance the 2 loops? i now regret going with 2 loops and wish i would have just done 5 or 6 jets on 1 loop but i trusted my builder as he said he has used this design numerous times and it worked well. i will try to find out exactly how much spa suction i have and let you know. i told my builder that i was very pleased with this project so far but if the spa did not work right it would ruin everything for me. before i signed the contract i told him i needed a spa that "rocks" and he assured me i would not be dissapointed. i hope there is a fix but i am prepared to rip-up the spa.

 

[JasonLion]

A flow restriction would account for your experience. That could be a pipe narrower than was needed, or a rock in one of the pipes. Running only a few jets at a time you can still move enough water through the pipe, but the restriction becomes more significant as the flow increases. But other things could do it as well, high flow jets, partially broken pump, etc.

 

[mas985]

mas985-thanks. so if i understand you, when somebody has 2 loops and they are not in balance the waterflow will come through 1 loop and not both loops equally? thats why i am getting all the pressure coming out of just 4 jets and not all 7?

Water likes to flow the path of least resistance, then again so does everything else. So unless each path is equal in length, fittings and jets, water will tend to flow more down the path with less head loss. This equalizes the head loss down the paths but the flow rates are different.

is rollin thunder correct about the 8 jets?

Even if you had 4 jets on each loop, it doesn't mean that the paths would be balanced. There are other factors.

also,why would the plumber use different size pipe for the loops?

Sometimes it is more about convienence than a good design. I have seen builders do a lot of stupid things so it wouldn't surprise me. It is unlikely that he did but you should check anyway.

i will try playing with the valve and see if i can get equal flow to both loops. the builder did tell me i would lose some flow when i turned on both loops but i thought the flow would be equal to all 7 jets. if i have enough suction it seems a simple fix would be to add a 1.5hp booster pump to the 3 jet loop and leave the 2.5hp for the 4 jet loop. but can this be done if i dont have 3" suction line?

It would be a bit iffy to have a 2.5 HP pump and a 1.5 HP running on a single 2.5" line. Double check the design and also see if you have multiple lines. Three 2" lines or two 2.5" lines are equivalent to a single 3" line.


if the pressure side measurements come out high does that mean i can not add power to fix the problem? i will get you the other info you wanted but based on the info you have what do you think is the chance that i will have to rip-up the spa?


I don't think you should have to rip up the spa. This problem should be fixable with the plumbing that you have. What is really important though, is to fully understand how the PB intalled/designed the plumbing. Otherwise, it is guess work.

See above comments.

Also, the order in which I would try things are:

1 - Make sure pipe are clear of debris.

2 - Adjust three way valve to equalize flow between loops.

3 - Add ball valves to each loop.

4 - Add second pump but you need to make sure that the plumbing will support it. Again, this should not be necessary because a 2.5 HP pump should be more than enough for 7 jets.