Something wrong in returns

[pdalton]

My pool pump pulls water through three valves = I call then East (E), West (W) and Center (C). "Center" is from the two floor drains, "East" and "West" are skimmers.

Today I noticed that the East and West are pulling water in differently. The East is very active and has a really good flow, but the West (same elevation in the pool) is pulling much less water and seems to be draining much slower.

So I tried different configurations of the 3 valves (each on (+) or off (-) with the pump on at full speed.

I'm not exactly sure what this tells me, So I would appreciate others' thoughts or suggestions. Here's what I found, using a 1-10 scale to express the strength of the flow as viewed through the pump lid and through the skimmer openings.

Valve positions Apparent relative flow into pump Activity at East Activity at West
C+ E+ W+................................10............................8....................3
C+ E+ W- ................................10............................8.................... 0
C+ E- W+................................8............................0....................3
C+ E- W- ................................8............................0.................... 0
C- E+ W+................................8............................8.................... 0
C- E+ W- ................................8............................8.................... 0
C- E- W+................................0............................0....................0
C- E- W- ................................0............................0....................0

From the above, I assume SOMETHING isn't right somewhere between the W valve and the W skimmer - perhaps a blockage or a crack or break in the pipe so pressure is lost? Maybe some problem with the W valve (Jandy).

But what doesn't make sense to me is seeing movement at the W skimmer when both C & W are on (regardless of whether E is on or not); but not seeing any movement at the W skimmer when both W and E are on, but C is off?

The pipes are all the same size (at least from the 3 valves down into the ground - I can't see any more than that), so shouldn't the suction pressure be the same?

If so, how can C in the open position cause movement at W when E is closed & W is open, but E in the open position can't cause movement at W when C is closed and E is open?

What else can I do to try to figure out this problem and how do I fix it?

Thanks.

 

[jblizzle]

I agree, that does not make much sense.

Do you have a picture of the pad and valves?

 

[pdalton]

I agree, that does not make much sense.

Do you have a picture of the pad and valves?

I have photos of the valves & each of the two skimmers for the several configurations. However, I can't upload that many. So here's just the one showing three valves, all ON:



Paul

 

[jblizzle]

What would also be telling, would be the filter pressures in the various valve settings.

Those 2 picture you show for the East and West skimmers sure look like similar flow to me, yet you call them 8 and 3?

The height and floatation of the weirs on each skimmer could greatly skew the apparent flow. Meaning the flow rate could be the same, but just the weir could make it look like more or less flow.

 

[Jimrahbe]

P,

I think you are making a problem where none exists... I assume one of the skimmer is close to the equipment pad and one is further way.. this alone will cause them to have difference flows.. And the configuration of the plumbing/valves makes it even less likely that they would all have the same flow..

What is the problem that you are trying to solve?

If you want to make sure that the West Skimmer is not clogged (which I doubt)... just open only the West valve and close the East Skimmer and the Main Drain.. I would run the pump at about 2500 rpm and as long as the pump works and does not run out of water, you are good to go..

Thanks for posting,

Jim R.

 

[pdalton]

Thanks. Well, I don't know what to say about that West skimmer. Looking at them above, I agree that those photos make it look like the East and West skimmers are about equally active when all 3 are open, but it really doesn't look that close when "live", rather than a photo.

And it's true that the West skimmer IS farther away from the pump than the East Skimmer, so maybe that does account for some of what I've been seeing.

But I noticed something else today that I hadn't seen before.

When the East and Center valves are off and only the West valve is on, there is absolutely NO movement at all at the West skimmer. Seems like there should be. I suppose that might mean the distance to the West skimmer is too far for the pump (running at 3450) to be able to pull water all the way from that West skimmer. And perhaps the movement I see in in the West skimmer when both the W and C valves suggested the moving water from those floor drains creates something like a venturi effect that adds just enough vacuum to cause the water at the West skimmer to draw better.

However, when only that W valve was open (C & E were closed), after I confirmed there was no movement at the West Skimmer, I came back and looked into the pump window. The new thing I noticed was I could see just a bit of water movement in the filter basket, BUT the water level was remaining FULL. If the pump couldn't pull hard enough to make water move at all in the West skimmer when just W was open (and C& E were closed), shouldn't the pump nevertheless have sucked down the water in the filter basket so it would be emptied (starving)? Since it didn't do that, from where is the pump pulling the additional water keeping the filter basket full? After seeing that., I returned to the West Skimmer and again confirmed that there was no water movement in that skimmer at all.

I sure don't want to be creating a problem if there isn't one. Maybe it's just that I don't understand enough about hydraulics so that my assumptions about what I should be seeing are wrong?

Paul

 

[Jimrahbe]

Paul,

You really do not want your skimmer to look like a toilet bowl when flushed...

If you had just the far skimmer running and the pump did not run out of water, then the water has to be coming from somewhere...

In theory, the Weir door should float up and down and allow the same amount of water into the skimmer as the pump is sucking out.

For an experiment, you can manually hold the Weir door up and you should see the water in the skimmer drop and swirl like a toilet...

At 3450, I too would have thought you'd would see some movement. Is the water level in the middle of the skimmer mouth or much higher?

That said, you have never told us what problem you are troubleshooting? It really does not matter if both skimmers have identical flow...

Thanks,

Jim R.

 

[jblizzle]

Are you sure the West valve is not the floor?

 

[Jimrahbe]

Are you sure the West valve is not the floor?

Jason,

That would make more sense.....

Jim R.

 

[Dodger]

If you have any measurable small debris that normally gets through the skimmer basket holes, you could try skimmer socks to see if the West skimmer is taking much in. I recently started using the socks and to my surprise, found that the skimmer close to the pump is taking in about 2-3x as much debris as the one 40 feet away (as Jim posited). Water flow in the 2 skimmers is not that much different to the naked eye, and floating pool items don't show a strong preference for one side or the other. But I think the pollen and small twig haul tells the story of water flow really clearly. And it also tells me that both skimmers are working.

 

[pdalton]

I finally had a chance to get back and recheck more closely in light of everyone's comments. Jason had the answer to the real problem: The valve markings were wrong.

The valves were marked when we bought the house several years ago and I've just assumed all along that the labels were correct. But this time when I rechecked, I completely ignored the and only checked the flow at the pump and whether there also was flow at either of the skimmers. As Jason suspected, the valve marked as "West" actually draws from the floor drains (Center) and the valve marked as "Center" actually draws from the West skimmer. ("East" was correct).

That, plus taking into account that the West skimmer is about twice as far from the pump as the East skimmer, explains what I was seeing, including the much weaker draw at the West skimmer.

Thanks to all for helping me with this "problem" that really wasn't!

Paul