any negative to running suction only from skimmers? Even at the 125 GPM rate on a single skimmer? That's a lot of suction but I guess it would be hard for someone to get 'stuck' unless they were trying.
Spa/Pool Pipe Size Question after reading Hydraulics 101
- Thread starter markmac
- Start date
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Earlier, you said there were two skimmers. Has that changed? For extra safety, you can use an equalizer port on each of the skimmers.
You can't put 125 gpm on a single skimmer. Check the skimmer installation manual for the gpm limits.
Also, you should not exceed 6 ft/sec for any suction line.
If you really need 125 gpm, the main drains would probably be helpful, but do you really need that much flow?
If yes, I would do a 2.5" pipe for the main drains.
Still two skimmers. Was just considering whether to drop the main drains but sounds like I should leave them.
in that pic, is the equalizer port what use to be plumbed to the main drain years ago? I had one on an old pool years ago.
in that pic, is the equalizer port what use to be plumbed to the main drain years ago? I had one on an old pool years ago.
In previous posts I was outlining how to pull/push 125gpm for 7x7 overflow perimeter spa. My plan is two pumps pulling 60gpm each, both on 3” separate lines. One would pull from one skimmer, and one pump pull from main drains.
if I drop the main drains, I’d pull 60gpm from each skimmer which should be okay, but the pumps could pull a lot more so hence my question on what impact that would be if they jumped up to full RPM, pulling from a single skimmer.
seems like I need main drains to have a buffer on the suction side. I do however see a lot of pics here with dual drains installed on the sides of new pools vs floor.
A single Intelliflo can do 125 gpm as long as the plumbing is correct. No point in using 2 pumps.
Yes. However I am putting a second pump just for spa jets, so figured I’d do the plumbing and have it also pull from one skimmer and push 60gpm, while pool pump pushes other 60gpm, both on separate 3” limes. mas985 did the math for me a few posts back, and the two pumps would run at less than half of a single.
if I’m buying a second pump anyway, the plumbing seems cheap to get as much flexibility as possible, and run everything at less power.
I’m probably reaching the point of over thinking this. However it’s probably because everything will be permanent in the Gunite and going back won’t be an option, so just want to make sure all options considered and max flexibility is available.
60 gpm is probably the maximum limit for the skimmer.
Check the installation manual for the gpm range.
Normally, I would skip the main drains, except for when you need high flow.
Check the installation manual for the gpm range.
Normally, I would skip the main drains, except for when you need high flow.
Maybe it’s best to just add a dual wall mounted suction instead of plumbing it to the skimmer.
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Most every pool built with a single skimmer exceeds 60 gpm at some point.
Two skimmers can easily handle 125 gpm.
If you really want a third port, you would be better off with a third skimmer.
Last edited:
Most skimmers are rated for a maximum of about 60 to 75 gpm.
In my opinion, good design practice is to stay substantially below the maximum rating.
The velocity in the plumbing should be kept below 6 ft/sec, which is 63 gpm for 2" pvc.
Excessive flow runs the risk of the skimmer running dry if the water level in the pool is down.
If the skimmer basket gets any significant amount of debris, that further reduces the capacity of the skimmer to provide enough flow.
For 125 gpm, I would definitely want more than 2 skimmers.
In my opinion, good design practice is to stay substantially below the maximum rating.
The velocity in the plumbing should be kept below 6 ft/sec, which is 63 gpm for 2" pvc.
Excessive flow runs the risk of the skimmer running dry if the water level in the pool is down.
If the skimmer basket gets any significant amount of debris, that further reduces the capacity of the skimmer to provide enough flow.
For 125 gpm, I would definitely want more than 2 skimmers.
Spa heating time is related to the heater size, not the flow rate.
Here are some of the ways that are used for pool/spa combos:
Jandy Valve Plumbing Schematics - INYOPools.com
Jandy Valve Plumbing Schematics - Learn how to plumb your swimming pool and spawww.inyopools.com
This the one you would likely want to use:
View attachment 146088
Just make sure you don't have too many jets for the spa jet pump.
@mas985
any issue if both pumps share the same spa suction line? It would be an either/or selection? I suspect it’s not advised as they would be fighting one another when not 100% to either/or.
My thought is the pool pump heats spa as shown in the image, and cycles as it heats the previously heated water. Then when at temp, switch to spa pump that just runs jets? Or should they really be on two separate suction lines?
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Sharing suction lines can be a bit complicated and you would need to add check valves to each pumps suction line so that when that pump is off, the flow isn't pulled through the pump. Also, if some of the skimmer water is not going through the filter, there is a possibility that debris could make it back to the spa at fairly high velocity which might not make it a very comfortable situation. So if you still want to use 2 pumps, then I would keep them on separate loops and have the two skimmers on the pump with the filter and then use a split wall port for the pump without the filter.
Last edited:
@mas985
Thanks for the suggestion. I was trying to pencil everything out, and started to wonder what I'm gaining (or losing) by trying to isolate the Jet pump, with the minimal amount of Head loss. Setting aside your valid point about the skimmer and no filter (replaced by split wall ports), I took one of the dual pump layouts from the site you linked earlier, and tweaked it to sharing the Spa Main drain. The reason I want to try and share the main drain is to heat the spa, and then switch over to a pump dedicated to the jets (avoiding filter/heater head loss).
Am I breaking the rules anywhere with this layout? The Spa drain would be either/or, and have the check valves for protection. With the plan for two Intelliflo XL, am I more than covered and should just simplify my life/plumbing, and run it as in the Jandy diagram also attached here? Am I over complicating this, just to avoid running the XF a little harder when the 6 spa jets are on (assuming I confirm Jets on the low end ~10 GPM)?
For reference, the modes I am envisioning;
1. Spa Heat Mode: Pool pump pulls 100% from Spa drain, heats, and sends 100% back to Spa via overflow. Equal in/out volumes of water.
2. Spa Mode: After Spa is at temp, switch to spa mode, Spa Pump pulls 100% from Spa drain, and returns 100% to Jets. Pool Pump pulls from pool drain/skimmer, and runs waterfall(s) if desired.
3. Skimmer Cleaning: As shown here, both pumps run at higher RPM, pulling from Skimmer and Pool main drain. Spa using overflow return, and Pool using Pool returns. For a sub-portion of schedule, push both Pool and Spa pumps return to Spa Overflow lines.
4. Normal daily filtering. Both pumps on set schedule at low RPM, returning via SWG as needed.
I can see it all working, but it does seem overly complicated to ensure Spa overflow GPM, and to max Spa jet pump head loss.
Thanks again for all your insight!
Thanks for the suggestion. I was trying to pencil everything out, and started to wonder what I'm gaining (or losing) by trying to isolate the Jet pump, with the minimal amount of Head loss. Setting aside your valid point about the skimmer and no filter (replaced by split wall ports), I took one of the dual pump layouts from the site you linked earlier, and tweaked it to sharing the Spa Main drain. The reason I want to try and share the main drain is to heat the spa, and then switch over to a pump dedicated to the jets (avoiding filter/heater head loss).
Am I breaking the rules anywhere with this layout? The Spa drain would be either/or, and have the check valves for protection. With the plan for two Intelliflo XL, am I more than covered and should just simplify my life/plumbing, and run it as in the Jandy diagram also attached here? Am I over complicating this, just to avoid running the XF a little harder when the 6 spa jets are on (assuming I confirm Jets on the low end ~10 GPM)?
For reference, the modes I am envisioning;
1. Spa Heat Mode: Pool pump pulls 100% from Spa drain, heats, and sends 100% back to Spa via overflow. Equal in/out volumes of water.
2. Spa Mode: After Spa is at temp, switch to spa mode, Spa Pump pulls 100% from Spa drain, and returns 100% to Jets. Pool Pump pulls from pool drain/skimmer, and runs waterfall(s) if desired.
3. Skimmer Cleaning: As shown here, both pumps run at higher RPM, pulling from Skimmer and Pool main drain. Spa using overflow return, and Pool using Pool returns. For a sub-portion of schedule, push both Pool and Spa pumps return to Spa Overflow lines.
4. Normal daily filtering. Both pumps on set schedule at low RPM, returning via SWG as needed.
I can see it all working, but it does seem overly complicated to ensure Spa overflow GPM, and to max Spa jet pump head loss.
Thanks again for all your insight!
Attachments
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Your spa is not elevated so you really don't need check valves.
The jet pump should pull from either the spa MD or the pool MD. It is really a waste of a skimmer without going through a filter. Why not swap the pool MD with the 2nd skimmer so you are actually filtering the skimmed water?
You will need a full controller to automate all the valve switching to accomplish this so make sure there are enough valve actuators.
The jet pump should pull from either the spa MD or the pool MD. It is really a waste of a skimmer without going through a filter. Why not swap the pool MD with the 2nd skimmer so you are actually filtering the skimmed water?
You will need a full controller to automate all the valve switching to accomplish this so make sure there are enough valve actuators.
Great idea on swapping the skimmer with Pool MD! Only issue I see is pool MD never gets filtered. Spa MD does when heating.
You mentioned above that I should use check valves on the suction lines in case one pump is off. Or were you speaking to the SPA overflow return check valve as not required?
I'm planning 5 or 6 IntelliValves. I don't see switching between heating spa vs pool as something I would do more than a handful of times a year and I can walk over for that. I was also looking at Valve D as optional, as it only allows for a heater bypass, and I'm not seeing a lot of value there, unless I'm missing why I would really need a heater bypass.
Am I losing anything considerable by adding a small filter to the Spa? Or do the benefits outweigh the filter by having more flow available to the jets, with less head loss?
You mentioned above that I should use check valves on the suction lines in case one pump is off. Or were you speaking to the SPA overflow return check valve as not required?
I'm planning 5 or 6 IntelliValves. I don't see switching between heating spa vs pool as something I would do more than a handful of times a year and I can walk over for that. I was also looking at Valve D as optional, as it only allows for a heater bypass, and I'm not seeing a lot of value there, unless I'm missing why I would really need a heater bypass.
Am I losing anything considerable by adding a small filter to the Spa? Or do the benefits outweigh the filter by having more flow available to the jets, with less head loss?
Last edited:
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
You need to be able to heat the spa so the SPA MD needs to be accessible to the heater pump. You don't really need the pool MD except when using the overflow.
You only need to use check valves if both pumps share the suctions lines at the same time. But the valving you have would not allow that anyway.
The bypass is nice to have should you need to work on the heater. Otherwise it can shut down the whole pool.
I don't think you need a filter for just the spa. You can filter using the other pump plus you have the SWG there too. If you really wanted a separate system, you would need both.
I actually edited my last post as I realized your first point. I couldn't circulate hot water in the spa. Doh. For the check valve, do I need any on the return side? In the Jandy image, I assume their included for the solar option being elevated. All the Pad in/out plumbing termination will be above the spa by at least a few inches.
As I'm going to use a Robot, I guess it would make more sense to put the Pool MD on the wall, instead of the floor. Then the MD shouldn't really be pulling much of any debris via the SPA pump.
Really, thanks a lot for all the advise. I don't know how I could write a check to a builder and take the basic setup, when this much thought has to be considered.
As I'm going to use a Robot, I guess it would make more sense to put the Pool MD on the wall, instead of the floor. Then the MD shouldn't really be pulling much of any debris via the SPA pump.
Really, thanks a lot for all the advise. I don't know how I could write a check to a builder and take the basic setup, when this much thought has to be considered.
- May 3, 2007
- 18,095
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
When you have solar, you need a check valve right after the filter so water does not flow backwards through the filter. The Jandy picture is really due to elevated spas. There you need check valves so the spa does not drain to the pool when the pump shuts off. In your case, the levels are close enough that it doesn't matter. The spa level will equalize to pool level when the pumps are off depending on the valve settings. If you don't want any of the water to drain out of the spa when the pump shuts off, then you need a check valve. But I would put them at the output of the spa jet pump and the 3" spa return line from the heater. Check valves on suction lines should be avoided if possible.
MD's don't really draw in very much debris at all unless you push it directly into the cover holes with a brush. That's why you don't need a filter for the spa jets if it is on it's own loop with the spa MD. However, for skimmers, a filter is a must.
MD's don't really draw in very much debris at all unless you push it directly into the cover holes with a brush. That's why you don't need a filter for the spa jets if it is on it's own loop with the spa MD. However, for skimmers, a filter is a must.
Thanks. So I don’t need the check valves on the suction? I figured it was a safe bet in case valves didn’t close right and the pumps would fight each other.
what about 2-way valves on each suction line? Are the also not advisable, so pump can always pull from somewhere?
what about 2-way valves on each suction line? Are the also not advisable, so pump can always pull from somewhere?