pool/spa plumbing problems

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In your last post you said 1 HP Northstar but in your first post, you said 2 HP Northstar. Which is it or do you have two pump?
 
I have 2 pumps. a Hayward NS 2hp for pool/spa and a Hayward NS 1 hp for the waterfall. A local pool professional said the 2hp was way too big and that all I needed was a 1hp. He also told me about how much I was spending on electric.

I decided to swap the pump around to see the effect(the same things were happening with the 2 hp pump btw). Everything I have been posting is since the 1hp is on the system. I just played with it again and notice that when I use the Hayward Navigator pool vac from a vac port, I am unable to draw only from the vacuum(I still need to utilise a small bit of skimmer) or I lose prime.

If I pull from the skimmers the system works fine. From the main drains a small bit of air. From the skimmer only, it begins to cavitate, and spa is a total loss.

So in addition to changing the spa suction(I will use 2" flexi pvc from each spa drain and bring together in 2x2x3 Y Wye joint) using 3"pvc and flexi pvc I can shorten run to 85'. The spa return will be similar but with 2.5 " The main drain and skimmer will always be used in combination so I can live with the main drain limitation. And increase the size of the vacuum line to 2.5" with a run o 59".

If I use the Epump the unions are 2.5" so I also plan on changing the supply 3 way valve to a Jandy Large Neverlube. Everything on the outlet size is 2" so I will leave it 2" pipe untill after the salt cell . After the 3 way valve I will increase size to 2.5" to the spa return using 2.5" pvc and 2.5"flexi pvc for turns. Should I use Cpvc after the heater because of temperature issues?

Looking back at the plans for the pool it even states that for 6fps flow max and 86' run I need 3" pipe. 118' run I need 4" pipe. I wish I had looked at the plans and watched him closer!
 
It sounds like you might have an air leak that needs to be resolved before you can get good info.

What is the elevation of the pump relative to the pool/spa?

A 1 hp pump will not give you enough gpms to properly backwash a 72 sq ft filter.

You can connect a vacuum gauge to either the hair and lint strainer drain plug or tap a hole into the suction manifold to find out whether the current condition of your piping is operable. With that info Mas could determine what the best course of action would be.
 
I have checked for air leaks around valves, fittings and the pump. No luck. Looking at the original plans I see there is a dual suction inlet system and atmospheric vent system. Due to the strong suction(long length and small pipe size), when in spa mode as the valve closes to 100% spa suction I immediately lose prime and basket is 1/2 full. That might be the problem, I will check when I get home. Even if I have a stone or something in the line I now see the plans(and everything I have learned from all of you) that the pipe size is way too small for that long of a run(max flow rate, pump and spa jet requirements) enlarging the plumbing will take care of everything. The pump is on same level as pool and the spa is 1.5' above pool.

I will not use flex pvc as I didn't want problems in the future. Using flex pvc on the corners allowed a shorter run, and using solid pvc will be closer to 95". Should I use 4" on suction side(for the majority of the run) and 3" on the return to the spa? A few extra dollars is worth it to me.

I plan to change the 5 spa jets. Any recommendation of a good quality? A mix of spinning and others.

Looking at future pumps I know that my current 1 hp is too small for everything I want to do with the spa and filter. And the 2hp is expensive to run for just pool recirculation and probably very inefficent due to a hard live the last 5 years. Using the Jandy Epump 2.0 should give me everything I need, and work well with my Jandy Aqualink. I might also look at the Vac-Alert. Will this work that much better than the current vent system on the spa?
 
Upsizing the pipe would likely give you about 10% more flow but it depends on the back pressure of the jets that you choose. If most of the head loss is in the jets, then the pipe is unlikely to benefit you much. If you choose low pressure, high flow jets then the pipe size might help a bit. You might want to settle on the jets first and then decide on the pipe size.

Also, there is such a thing as too little head loss for pumps. If the pump operates to the right of the best efficiency point, the internal head loss increases, noise increases and stress to the motor shaft increases. A rule of thumb is not to exceed 110% of the BEP. Going to 3"/4" pipe might do that so I would also add a valve on the spa return to reduce flow rate if necessary but then that kind of eliminates the need for larger pipe. But if you choose high pressure, low flow jets (15 GPM), then that should take care of it as well. But high flow (25 GPM), low pressure jets may not.
 
It appears that it is beginning to come together. I plan to start digging this week and upgrade pipe and pump.

Things I plan to change:

1. Spa plumbing suction to 4" and return to 3". Large Jandy 3way never lube and 3" to pump.

2. 2.5" on pool vac line and skimmer line.

3. 2.5" from pump to filter, heaters, Aquapure

4. Bypass on both heaters.

5. New drain covers on pool and spa

6. New Waterway spa mini-jets

7. See if I can tie in existing SVRS system to spa suction, otherwise check on Vac-Alert

8. Install Blue-White F300 on 2.5" pipe after filter and before heater. I will have dia x 10" before meter and dia x 4 after meter.

9. See how system runs with 2hp and 1 hp pump. Check pressures and determine which pump I get(I am leaning to the Jandy epump and firmware upgrade because of compatability issues).

10. What do you think of having spa return to a manifold and then to individual jets for even flow? Overkill or good idea?

11. Does it matter where spa blower joins the spa returns(near equipment or near spa)? Laminar flow issues?


This is what I have put together from all your advice. Does this sound like a reasonable plan of action now or do you have any more advice or changes I should think of? I sure don't want to go through all of this and miss something just to save a couple of bucks.

Just wanted to say thankyou again for everyones guidance and expertise.

When plumbing the system is there any guidlines you might have? ie. elbow butted up to Jandy 3 way valve or sould there be a set amount of distance between joints? I plan to run 3" pipe to pump supply(suction) in the length of 5 x diameter(15").
 
One more thing to be aware of is that if you go with 4" suction and 3" returns plus bypass the pad, the flow rate acheived may exceed the best efficiency point of the pump by close to 40% on full speed which is a run out condition. This can put excess stress on the motor shaft and may lead to premature failure of the motor bearings.

I think the bypass is still probably a good idea with high flow rates to save your filter but there is such a thing as too little head loss for pumps. If you decide to go this route, you may want to consider running at lower speed and/or having a throttling valve on the return side to reduce flow rates. But if you do either of those, then it really doesn't make sense going with 4"/3" plumbing. Even if you downsize the plumbing to 3"/2.5" you may still have fairly high flow rates. A rule of thumb is to target +- 10% of BEP but not to exceed +-20% of BEP. The 3"/2.5" plumbing is less than 20% but not by much and it would give you more than enough flow rate for the high flow jets. I estimate about 140 GPM @ 47' of head. But even that is on the far right of the head curve.

One more question. If you have this jet setup, the jet nozzles are 5/16" and only require 10 GPM each so your current setup should have worked properly even with the 2" pipe but it sounds like something else is still wrong. 5/16" nozzles would have produced about 25 PSI in the filter with the 1 HP NS and only about 10" hg. If the jet nozzles have been removed, the spinners will not work properly, PSI will drop and suction increase which may be opening the release valve. Have you checked to see that the nozzles have not been removed or even expanded in some way?
 
My thought was that I could use 4"suction and 3" return, run through the filter, heater and aquapure. I might change the spa jets to 15gpm flow heads. Is it better to use the same size pipe on suction and return. Then using the Epump I could adjust flow down to about 75gpm so it should not exceed the design efficency of the pump(is my understanding of the variable speed pump correct?). When in spa mode the Jandy JVA will route water through the heaters. My thinking is that by bypassing the heaters in everyday pool circulation I can extend the life of the heaters by not sending water through them. Normal pool circulation would be 30-35gpm for about 10-12 hours/day. Hopefully saving electric.

Bypass on the heaters is easy using the JVA, but I have not been able to figure a good method to bypass the filter or the Aquapure when using flow of 30-35gpm for normal circulation then changing to 75gpm in spa mode. The filter is a Hayward DE7220 which has a design flow rate of 144gpm.

The jet setup does appear to be what I have. Before I start digging I will take them apart and see if there is an internal problem.
 

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So if I understand everyone correctly,

1. The plumbing at 2" for 95" and 15 elbows(both suction and return), the spa will not physically operate, regardless of some other possible leak or blockage.

2. Therefore, I need to replumb to a larger pipe for suction and return.

3. For energy savings and life of my epuipment I need a a 2 speed or variable speed pump. The variable speed epump will allow the exact rpm to operate the pool recirculation and spa flow for equipment specifications(flow rate through filter and aquapure in recirculation mode and heater and flow needs in spa mode). There is not a need to operate the pump at full capacity is there? A 2 speed pump might not be the proper curves for my plumbing, equipment and/or spa jet requirements. The extra performce of the pump should allow me to change spa jets to a higher flow requirement if I desire. Essentially replumb then with the flowmeter adjust pump rpm to give proper flow rates for each configuration.

4. Since I believe that I must replumb the system, the cost of increasing the size of pvc and fittings is minimal and should be recovered long term with a reduced electrical drain(reduced rpm) on the epump. I live in Florida and it is only a matter of time untill the electric rates trend upward towards California's rates.

This spa has been such a huge dissapointment and bother since it was built. I don't mind overengineering things so that I know it will work and I will never have another problem with it. I only want to do this once.

Thank you again all your help, guidance and expertise. I along with others really do appreciate it.

Steve
 
First, I don't believe that the internals and nozzle for that mini-jet assembly is interchangeable with anything else. So you may be stuck with that size. For a 5/16" nozzle, Waterway recommends 10 GPM for moderate strength and 12 GPM for a strong jet. So for 5 jets, that is 60 GPM at most.

#1 - Your current setup with the 1 HP NS pump should have provided 58 GPM @ 73' of head which would have been 11 GPM per jet. The strength of the jet should be moderate but working properly so yes, your current setup should work. Also, the suction for that would have been only 9.8" Hg., so it should not have opened the SVRS vent if that is really what you have. The bigger question right now is that your current setup should work but why isn’t it? I believe that air is entering in from somewhere that is causing the pump to lose prime which is the biggest problem. Fix that first, and you might find out that the jets are fine. Try plugging the air vent and see if things don't work better. Also, are you sure that it isn't the venturi air inlet? If not, do you know where the air inlet is; close to the spa or near the pad? If the air inlet is near the pad, then you need an air blower.

#2 - You would benefit with larger pipe but it may not be necessary to get things to work properly. You may find out you have a collapsed pipe somewhere which is restricting flow on the suction side so it needs to be replaced anyway.

#3 - There is no need to run the pump at full speed but if you don't, there may not be a need for very large pipe either. The whole reason to go with large pipe is reduce head loss at high flow rates. Running at 60 GPM or lower, really doesn't require that large of a pipe and under most situations 2" would be fine but at 95', 2.5" would have been a better choice.

#4 - I am not yet convinced that you have to replumb but again, it wouldn't hurt. As to the size that is up to you but see the analysis below.

BTW, did you verify that there is indeed a 5/16" nozzle inside of the jet? This is key to understand the expected performance of the spa. If you can confirm that, I can tell you within a reasonable amount of error, what kind of performance you can expect with each size pipe. I went ahead and assumed that it is a 5/16" orifice and ran some cases with various size plumbing. All of these cases assume the Jandy JEP 2.0 which I think you will be using no matter what. I also assumed that you would set the speed such you get 60 GPM no matter what setup you end up with.

Current plumbing (95'-2"/2"): 3360 RPM, 60 GPM @ 75.6' of head, 10.6" hg., 1678 watts (note that even this config should work)

Config A (85'-2.5"/2.5"): 2991 RPM, 60 GPM @ 58.4' of head, 3.7" hg., 1273 watts

Config B (85'-3"/2.5"): 2940 RPM, 60 GPM @ 56.2' of head, 1.7" hg., 1223 watts

Config C (85'-3"/3"): 2871 RPM, 60 GPM @ 53.2' of head, 1.7" hg., 1157 watts

Config D (85'-4"/3"): 2839 RPM, 60 GPM @ 51.9' of head, 0.5" hg., 1123 watts

The biggest benefit is going to 2.5" plumbing and each step above that is a modest change. Also, remember that each of these configurations has exactly the same spa performance. The biggest difference is how much energy they consume.

But again, it is really important to find out what the current problem is first. You might end up replacing all of that pipe and find out it is something to do with the spa jets themselves and have to tear apart the spa to fix it.
 
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