Pump running time

[chezhed]

When we put the pool in during the summer, we ran the pump 24/7 for the first four months. Water chemistry and everything were great.

We put up a leaf net tent for mid-Oct to mid-Dec and cut back pump to about 10 hrs/day. No problems at all.

I've since cut pump back now to about 7 hrs/day and everything is still great, other than the near daily pool vacuuming needed because of spring debris (but that's another topic I'm researching on the cleaners forum 8) )

So how long do people usually run their pumps? Is six enough....12 overkill? 24/7 needed in summer? or is it the standard consultant answer....."it depends....." :lol:

 

[mas985]

It does depend.

There are several factors to consider. How much stuff drops in your pool, the turnover rate of the pool, and how clean do you want it to look.

With your pump, you are probably getting close to 90 GPM which means you have a turnover of 2 hours. Most pools need only one turnover a day so you might able to get away with as little as 2 hours per day.

If you have a two speed pump, you would double the time for low speed.

I hardly ever run mine more than 2 turns per day even in the heat of the summer so you probably wouldn't ever need more than 4 hours per day. During the winter, I drop my run time to 1/2-1/4 turn per day and that seems to be enough with cold water and no swimmers.

 

[Need to Learn]

Hi mas85,

I am out here in CA as well, Tracy. I would love to reduce my pump time with the cost of electricity. Is there a turnover rate calculation in Pool School or elsewhere?

I have only been running 4 hours a weekday during the off season, but was running 8 hours a day during the summer plus often during swim time as it also runs my slide. I wonder if I can not reduce both of these run times.

Thank you.

 

[Butterfly]

TFP members use all variations of pump run times Here's a thread:

pump-run-time-t7099.html?hilit=hours

 

[JasonLion]

Unfortunately, there isn't any simple way to figure out your flow rate, which is the key information used in calculating your turnover time. To find out your flow rate you either need a flow meter or an automotive vacuum gauge and a working filter pressure gauge. Given some details about your system we can take a guess at your approximate flow rate, which is what mas985 already did for chezhed.

 

[mas985]

Hi mas85,

I am out here in CA as well, Tracy. I would love to reduce my pump time with the cost of electricity. Is there a turnover rate calculation in Pool School or elsewhere?

I have only been running 4 hours a weekday during the off season, but was running 8 hours a day during the summer plus often during swim time as it also runs my slide. I wonder if I can not reduce both of these run times.

Thank you.

If you give me your filter PSI (assuming it is correct) and pump model, I can make a guess for you.

 

[Need to Learn]

Thank you all for your quick responses. I really enjoy this forum and have learned a lot by reading, and searching, and reading, and searching more...

Based upon my reading from this forum and information from my builder I believe my turnover rate is approximately 4 to 5 hours. Here is the data used to derive that. The pump is a Jandy Stealth 2.0 HP, model SHPF2.0. We are using the Pentair Triton II, TR140 which states a 7.60 sqft filtration area, 15 gpm/sqft fitration, and 105 gpm filtration flow rate. It operates at between 20 and 30 PSI.

Based upon the following information from my PB, "The flow rate on your pump is about 80 - 100 Gallons per minute. I say about because the amount of sweeps creates what they call restrictive head. The numbers are close but remember these are approximations." Our pool is 23,000 gallons; therefore the 4 to 5 hours for one turnover.

We have little debris in the yard and therefore it seems I could reduce my summer run time and possibly my winter run time.

Does this sound about right?

Thanks again!!

 

[mas985]

Why such a wide range in PSI readings? If that is the difference between a clean filter and a dirty one then I would say you are waiting way too long between cleanings. If the range is due to something else, then I would need to know that.

Having such a wide range in PSI values results in a vary large range in flow rates. Assuming 80% of the total head loss comes from the return:

20 PSI results in 129 GPM @ 60' of head
25 PSI results in 98 GPM @ 72' of head
30 PSI results in 50 GPM @ 86' of head

For that size pump, your PSI seems fairly low at 20 and would require really big pipes to keep the pressure that low. 30 PSI would be too high so my guess is that you are probably closer to the 25 PSI value but I need some more info to get closer.

What causes the large swing in PSI?

What diameter/length pipe runs do you have and are there multiple suction/return runs from pool to pad?

 

[Need to Learn]

Hi Mark,

I have been following the filter manufacturer's cleaning frequency instructions, "The most commonly used but less accurate indicator is to backwash when the filter gauge reading increases 10 PSI over the initial (clean filter) reading." This is because I do not have a flow meter and could not perform the alternative options. I double checked and at startup, the pool is just under a year old, the filter started clean at 21 PSI and returns there after a backwash. It is currently operating at 25 PSI. I did the last backwash in July when the PSI was at 28.

I have two skimmers and two 8 inch main drains. The drains are about 48 ft from the equipment pad; the skimmers are roughly 43 and 80 feet away from the equipment. The PB used 2.5" suction lines and 1.5" return lines. There are 7 returns. If it matters the PB was Premier Pools and Spas.

Please let me know if I did not answer any of your questions.

Tony

 

[mas985]

Yes I know manufactures will tell you to backwash at 8-10 PSI rise but flow rates drop considerably with such a high PSI rise so you would be much better off cleaning the filter more often. You might consider cleaning it at 25-26 PSI.

I need to know how many individual lines run pool to pad for both the suction and return.

So did the PB put in seven individual return lines pool to pad? (probably the only way you get 21 PSI)

Also, on the suction side, are there three individual lines pool to pad, one for each skimmer and one for the main drain pair? Or do the skimmers and main drain share a single 2.5" line from pool to pad?

 

[Need to Learn]

Will these images help address your questions? It looks like the lines are combined at the pool before the run to the pad. I have other images, but can only upload 3.

I just thought to add there is a valve at the equipment that allows for a flow/suction adjustment between the drain and skimmers. I know this has an impact on the PSI pending how it is set. Perhaps I have is set too far in one direction or the other.

Thank you for your advice on the filter cleaning frequency. I have previously read there was a downside to cleaning too frequently, something about filter efficiency.

 

[mas985]

Will these images help address your questions? It looks like the lines are combined at the pool before the run to the pad. I have other images, but can only upload 3.

I'm having a hard time determining the setup from those pictures although it looks like the return lines are larger than 1 1/2".

I just thought to add there is a valve at the equipment that allows for a flow/suction adjustment between the drain and skimmers. I know this has an impact on the PSI pending how it is set. Perhaps I have is set too far in one direction or the other.

Yes, this valve should be set such that both lines are 100% open. This is where the PSI is at it highest level. What is the PSI when you do this?

Thank you for your advice on the filter cleaning frequency. I have previously read there was a downside to cleaning too frequently, something about filter efficiency.

Yes it is true filters will clean better the dirtier they are but there is a trade off. The downside is higher head loss, lower flow rates and lower energy efficiency.

It sounds like you have at least two suction lines coming in and perhaps only 1 return line. If that is the case, then the reason the PSI reading is so low is because of the valve setting on the suction line. It could be that you are starving the pump of water. Do you see any air bubbles in the pump basket?

A picture of the pad plumbing might be easier for me to figure out what is going on.

 

[Need to Learn]

Mark, I really appreciate your patience and assistance!

I think you may be correct about the return line; it might by 2.5 to the pool and 1.5 at the pool or perhaps 2.0?

I set the skimmer/drain valve so that both suction lines are 100% open. The PSI moved from 25 to 26. Based on your previous suggestion I am thinking I should clean/backwash the filter this weekend. There were no bubbles in the pump basket. I do not believe the pump was starving, but may not have been operating efficiently given your information.

Attaching equipment pad images, and I see where there are 2 skimmer lines and one drain line at the pad coming into the valve prior to the pump. There is one primary return line to the pool where it splits off and there is also the cleaner line with the supplemental pump.

Is the math adding up yet?

 

[mas985]

Best that I can tell, you are probably close to or slightly over 100 GPM when the filter is clean but please report back when you backwash with the new PSI. A few more questions:

It looks like there are two return liines with a control valve. In the picture, only one is on. What is the other line for?

In one of the pictures, there seems to be some sort of water feature in the back of the pool. Is this what the second pump is for?

[EDIT] I going to revise my estimate and say that it could be as high as 120 GPM @ 64' of head. After lookinig at your plumbing in more detail, your return head loss could be on the low side since you have a very large filter, no heater and 7 returns even though you only have one return pipe.

 

[Need to Learn]

The clean filter, with the same open valve settings, is running at 23 PSI. The other return line is for the slide; and yes, the other pump is for 3 sheer descents.

So it sounds like our pool should be turning over every 3.2 to 4.0 hours. If I understand correctly, I should easily be able to reduce my summer run time from the 8+ hours; and I am thinking I can reduce my winter run time as well.

Here is a picture of the pool at sunset right after the build. Not sure how weill it will show up on the forum, but it looks better at night because the landscaping is still not done!

Please let me know if anything sounds incorrect; otherwise thank you again for all of your help!

Tony

 

[mas985]

Ok, things are making a bit more sense now. 23 PSI is closer to what I had expected with your plumbing. You are definitely less than a 4 hour turnover so I think you would be safe reducing your run time.

In winter, I run my pump 1/2 to 1/4 of a turnover per day and it seems to keep the pool fairly clean.