Changing from suction to return

[Dave31410]

When my pool was built, the builder plumbed three lines into one side of the pool. The two near the ends are returns. The center one was supposed to be for a pressure cleaner. I deleted the pressure cleaner and asked that the center line be tied into the pump suction to be used as a vacuum line, which I used a few times before getting a robot. Since then I have not used it. I am thinking of re-plumbing the line as another return. Would this be beneficial, and would I ever miss having a place to attach a vacuum hose?

 

[Dave31410]

Update: I figured out I can use the skimmer hose attachment if I need to vacuum.

 

[cfherrman]

Not really, your skimmer does all the work and if you split the suction it killed the skimmer.

If it was being correct you would need to take care if entrapment risks as well

 

[RMcGirr83]

I was thinking of doing the same (when I decide to convert to SWCG). Capped pipe was to be for vacuum robot. More returns the better.

 

[PoolGate]

Post a pic of your setup. Depending how it is plumbed it may or may not make a return difference. If nothing else though it will increase water circulation. I also have an unused pressure/return port for a cleaner that I have never used. I crack the valve though every once in awhile to keep the water in that pipe fresh. It also bypasses my heater and SWG if I would ever need that.

 

[Dave31410]

Not really, your skimmer does all the work and if you split the suction it killed the skimmer.

If it was being correct you would need to take care if entrapment risks as well

I don't have a main drain

 

[Dave31410]

Noted on the picture but the left ball valve would be omitted

 

[PoolGate]

On your setup I would always have some water coming out of the vacuum port but not get rid of it. You can probably find an eyeball that fits it if you want to be able to direct the water. You could also do a "poor man's" water feature like a rain spray by making a simple PVC water feature and connecting it to this port.

 

[duraleigh]

I would get an idea of the water flow before I changed anything. What is your current psi and at what speed?

 

[Dave31410]

I would get an idea of the water flow before I changed anything. What is your current psi and at what speed?

2 psi at 1750 rpm

 

[Dave31410]

On your setup I would always have some water coming out of the vacuum port but not get rid of it. You can probably find an eyeball that fits it if you want to be able to direct the water. You could also do a "poor man's" water feature like a rain spray by making a simple PVC water feature and connecting it to this port.

that is the plan. add an eyeball, and replace it with a spray when it gets hotter. The Jandy valve would balance the flow

 

[duraleigh]

With your psi that low, I would suggest a smallish eyeball (1/2") to keep your pressure up.....perhaps on your existing return line as well.

 

[Dave31410]

With your psi that low, I would suggest a smallish eyeball (1/2") to keep your pressure up.....perhaps on your existing return line as well.

Is the purpose of keeping the pressure up to maintain velocity coming out of the returns?

 

[duraleigh]

Yes! At 2 psi and going lower when you add that extra return, I think you would want more movement in the pool.

I believe it's a good idea to keep as much debris and dirt moving around the pool (to ultimately be captured in your filter) rather than having flow too weak and the pump not doing enough work to keep things stirred up.

 

[RMcGirr83]

Isn't 1750 at bit low on the RPMs? I would think a PSI reading at full RPMs would be a better judge.

 

[Dave31410]

Isn't 1750 at bit low on the RPMs? I would think a PSI reading at full RPMs would be a better judge.

My understanding is that the VS pump should be kept at an RPM low enough to activate the SWG cutoff switch, and high enough to promote circulation.

 

[PoolGate]

Yes! At 2 psi and going lower when you add that extra return, I think you would want more movement in the pool.

I believe it's a good idea to keep as much debris and dirt moving around the pool (to ultimately be captured in your filter) rather than having flow too weak and the pump not doing enough work to keep things stirred up.

I've thought about this. Wouldn't more low flow be the same overall flow as less higher flow? I mean return water is the same volume over time regardless of how many outlets you have, right? Note: I don't know squat about fluid dynamics.

 

[Dave31410]

I've thought about this. Wouldn't more low flow be the same overall flow as less higher flow? I mean return water is the same volume over time regardless of how many outlets you have, right? Note: I don't know squat about fluid dynamics.

Imagine you have a hose with no nozzle. Then place your thumb over the end of the hose to make a stream. The flow is reduced but the pressure is increased. Pool pumps are high volume, low pressure, so you want the pressure in the returns to be sufficient to create flow to the skimmer. Larger return openings would allow higher volume, but less velocity so that the surface flow towards the skimmer would be less.

 

[cfherrman]

I don't have a main drain

Not sure where a main drain came into this topic?????

 

[Dave31410]

Not sure where a main drain came into this topic?????

You referenced splitting the suction, and entrapment risk, which to me implied a main drain, but perhaps I misunderstood.