Pump time

I have a single speed pump, and I run it from 8-4 because it also circulates my solar. Not sure what low constitutes on your pump, but I would say anything 24/7 is overkill unless you are slamming. Figure out how many GPM your pump is and divide it by the size of your pool. That is how long you should pump to turn over the water once a day.
 
I think if you asked 50 TPF members their run time, you might get close to 50 different answers based on their pool size and local conditions. After all, mixing chemicals and keeping the water surface clear of debris are our number one concerns with pump times (and creating FC for SWG owners). But you might like to read the TFP Pool School - Determine Pump Run Time page for some more info if you haven't been there already. Otherwise, I'm sure you'll start to see a few responses to your question. Have a nice weekend.
 
To answer that, first you need to know the time it will take your pump to turnover the entire volume of water in the pool. Then determine how much contamination you want to remove using "Gage and Bidwell's Law of Dilution for turnovers in filtering water":

So only 1 turnover of your water will result in 63% of the contaminants being removed while 2 will remove 86% and 3 removes 95%. Most states do not have a require number of turnovers per day for residential pools. It's safe to say that 1 is not enough and 2 or 3 is better.
Sorry but this is simply not true. Read the pump run time study in my signature. Pools can get away with only 2 hours of run time per day independent of pool size.

Plus the law's of dilution don't really apply to pool water filtering.
 
I run my Jandy pump at 1730 RPM for 18 hours out of the day (that's roughly 50 gallons per minute), I then run it for 6 hours at 2750 to engage the skimmers. The cost for 1730 is roughly 200 watts, the cost for 2750 is roughly 1000 watts. 200 watts to keep the water moving through the filter, that's quite cheap ( our energy rate is $.10 per KWh).

Our pool may be different from yours though, we have the venturi skimmers that work very well at slow pump speeds.

Also, pool pumps are impacted by how often they are turned on and off I just decided to leave them running.
 
Also, pool pumps are impacted by how often they are turned on and off I just decided to leave them running.
I don't think you have anything to worry about here. VS drives deliberately ramp the RPM up from 0 over a set period of time to prevent current surges. Turning it on and off is no different than changing speeds. Even a standard motor can be turned on and off several times a day without worrying about "wearing out" the motor. There is very little in a pump motor that would be affected by that.
 

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mas985 said:
+1 and reiterating for emphasis. This is the process I used to determine how long I should run my pump. I have been using the results I obtained by using the method described in this article for several years with great success. Of course, I do adjust the run time as needed for extenuating circumstances such as before & after pool parties, whenever there is a larger-than-normal amount of debris in the water, and adding granular CYA to name some.
 
mas985, you are correct in stating that the pumps do ramp up. I hadn't thought about that.

I agree with some of the articl that BoDarville pointed out. I'm a bit confused on some of the recommendations though.

In the "Determine Pump Run Time" article there is no guidance provided on pump speeds for variable speed pumps. Using a Jandy 2 HP pump, I can run the pump at 1730 RPM (50 GPM) and change the water in the pool every 6 hours (roughly), that's at 200 watts. I can speed up the pump to get a higher turnover rate, say 2750 but them I'm at 1000 watts. A five times increases in costs.

The pool builder advised that three turnovers a day was what they do at the commercial pools and I verified that the city requires a turnover rate of six hours for all pools. While I recognize that on a home pool this may be overkill, it is a well known standard and a requirement by the city. All other advise that I've read is all over the board between 1 and 4 per day and really doesn't have any documentation to back it up.

With the venturi skimmers and the variable speed pumps I can run the pumps slower for a lot longer and at a lower cost. Why wouldn't I do that?
 
Why not?

Do you leave all the lights on in your house when you go out or to bed?

No, because it is a waste of energy and pointless.

If you can accomplish the same thing with less run time, why wouldn't you reduce the run time?

You might want to read the run time study in my signature. As far as I know, there has never been another scientific study like it.


But I have to question some of your numbers, you said that the pump consumes only 200 watts at 1730 RPM and 50 GPM? Is this what the pump is telling you? There is not a VS on the market that can do that.

At 1730 RPM and 50 GPM, the Intelliflo uses 400 watts, the EcoStar 350 watts, the ePump 2 HP, 550 watts. I don't think your pump uses half the power as these high efficiency pumps do. One of the three numbers is not correct and most likely it is the flow rate. Did you measure the flow rate?
 
You should run it longer and slower. I run my pump for 12 to 24 hours a day at 1100 rpm and it uses 150 watts. Length of time varies based on how busy our many trees are.

Turnovers is a requirement for public pools. Public pools are regulated and have LOTS of people in them with who knows what diseases, viruses and pathogens. There is no documentation to back up turnovers in a residential pool because there is no official rule that says you have to have any number of turnovers in a residential pool. How can you prove that something doesn't exist? :)

But, since you are in charge of your pool you get to say how many turnovers are required.

The primary concern for sanitation in a residential pool is maintaining FC above the minimum level of chlorine for your CYA. Chlorine CYA Chart If FC drops below minimum then the pool becomes unsanitary and there is increased risk of person to person disease transmission.
 
I don't leave my lights on all the time, I am very energy conscious. Have one of the most energy efficient houses in Frisco TX. Frisco now uses most of the ideas that we originally put in the house, I don't take credit for this, the people that enforce the building codes in Frisco are awesome.

However, when I look at the documentation from Jandy, they show that at 47 GPM they are using 300 watts at 1730 RPM. If I was publishing this information I would use a number higher than the actual number to protect myself from a fraudulent lawsuit. Therefore, I believe that our pump using 240 watts (checked it and found this to be the number) is accurate. In addition, we use 2.5" plumbing everywhere and put in a filter that is twice the size of what the pool builder proposed so our head is actually quite low (clean indicator on the filter is well below the clean line after two months of pool use and both head pressure gauges are very low).

As to the flow rate, you bring up a good point. A&A will be out to install a flow meter within the next couple of weeks so that I can more accurately know what the pumps are pushing.

I like the idea of running the pool slower and longer. I too live in the Dallas area, in Frisco. During the winter I might slow it down but right now there is all kinds of trash in the air from the cottonwood trees.

I check the FC every day as well as the CYA, Alkalinity, Total Chlorine, hardness, etc.

pooldv, how is solar working for you? Our setup allows us to do that but I'm a bit concerned about our view of the southern sky. It's good right now but as our trees grow in the front (which faces south) we'll start to lose coverage in about 10 years.

We also took similar steps to what you are doing, put in everything we need for a heat pump, at 84 the pool is still to cold for my wife.
 
So I downloaded the latest pump measurement data from the APSP: http://www.apsp.org/Portals/0/Pool%20Pump%20Database/Pool_Pump_March_3_16.xls

The VSPHP270 Curve-C shows the following data point at 1730 RPM: 47 GPM @ 332 watts

So in reality their brochure embellishes a bit. These are much more reasonable numbers and fit better with existing VS pumps.

If your pump is using only 240 watts @ 1730 RPM, then the flow rate would need to be about 15 GPM (<Curve-B). It looks like you have fairly high head loss plumbing. Is the wattage from the pump readout?

Pump manufactures really can't misrepresent the performance of pumps anymore because if they want the Energy Star rating, the government requires them to publish pump measurement data. However, it appears that for marketing, anything goes.
 
Solar works great, it has given us many swim days where the pool would be too cold otherwise, also much quicker recovery from rain. Our pool is shaded more than half the day and our solar panels are also shaded part of the time. Pics in build thread, link in sig. We added a solar cover this spring, HUGE difference. I would try that first.
 
Here's what I have (still waiting for the water meter, just pinged the A&A regional manager):

Head is calculated using:

Pressure at Pump Inlet * 1.13 + Pressure at Pump Outlet * 2.31

2016-06-06_13-41-27.jpg

I'm looking forward to getting the flow meter. The information I'm getting here, which I'm finding very valuable makes me believe that I haven't quite figured out head, gpm and pressure.
 
Was the pressure measured directly at the pump or are you using filter pressure?

Also, are you measuring vacuum (in-Hg) on the suction side?

Also, do you have check valves?
 

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