Pump run time, pump speed, SWG cell setting - HELP!

[thejeff]

Hi all,

This is my first full season with my new inground FG pool. Finished a SLAM a few days ago and the water is beautiful. Chemistry is perfect, just waiting on warmer weather to start the heat pump for the season.

I have some questions :

1) Pump run time and speed - I have a Hayward Variable Speed pump. I do not have a lot of head on my plumbing so can run the pump at very low speed and get good circulation. I am under the impression that running the pump at a low speed 24/7 is the most efficient in terms of energy consumption. This is what I have been doing. Is this the best solution versus running at higher speed but intermittently? I am guessing that a higher speed will have stronger circulation and will force more dirt through the filter that perhaps would not get sucked in at a lower speed? What is recommended? I do not have a main drain, only 2 return jets in the shallow end and the skimmer in the deep end. Pool is only 26x12.5

2) SWG settings - obviously linked to point 1 above, SWG only runs with flow so if running 24/7, it appears like I need to have a VERY low SWG setting. Thinking around 10% maybe?. I have a T-15 cell with an 8800 gallon pool (I believe T-15 can provide chlorine for up to 40k gals at regular salt levels and 25k gals at low salt levels, so it is over sized). Pool Math tells me that at 100% power, the SWG T-15 cell could generate 19ppm FC per 24 hours in my pool. I assume this is not the low-salt version that I have so let's assume a bit less.

Before I spend too much time on trial and error, thought I would ask the forum!

Thanks in advance

 

[ajw22]

Determine Pump Run Time

To figure out how many hours you need to run your pump, you need to know how fast your pump works. You can find this here.

www.troublefreepool.com

Use PoolMath to calculate 3 ppm daily output for your chosen pump runtime and then fine tune from there as you how see your pool FC changes week to week.

 

[thejeff]

I have read Pool School and that article yesterday but it does not address my questions about energy efficiency or running a constant low speed and debris removal at lower speeds. Was hoping to get more detailed answers if possible.

 

[ajw22]

Higher pump speeds use more energy. 1200 rpm uses about 10% of the energy of 3400 rpm.

Your pump runtime and speed will be dictated by your SWG. That will be more then enough for proper filtering.

 

[Jimrahbe]

Jeff,

A faster pump speed will not suck more "dirt" out of your pool.. it might help the skimmers work a little better, but I run pretty slow and don't really see a lot of difference in skimming when I run a little faster..

I would think that running 24/7 (which I do) has got to be less energy efficient than only running the pump for a shorter amount of time. Seems to me that if the only factor is energy consumption you want to run your pump for the shortest amount of time possible..

That said, I run 24/7 for other reasons and it costs me less than $20 bucks a month to do it, so while I could save a few bucks on the electrical bill, I'd rather skim all the time and make chlorine all the time.. I have zero proof, but my theory is that it is harder on a pump to turn on and off everyday, than it is to run 24/7.. Only time will tell..

Jim R.

 

[thejeff]

Thank you! Did not realize the massive difference of running at lower speeds.

Ok, since my SWG is oversized, I guess it can easily adapt to any runtime/speed. So the first variable to solve first would be the run time. Based on the Hayward calculations, I could run the pump at 1200 rpm for 12 hours per day and get 2 turnovers.

Based on pool math T-15 cell, 19 FC per 24 hours at 100%, I should get 9.5 FC for 12 hours of run time. For a target of 3 FC per day, to start, I should then set my SWG to around 33% if only running 12 hours/day.


Jim, Thank you. Based on my math, running my pump 24/7, even at 1200 rpm, I would get 4 turnovers per day. Sounds like a lot but you are right that it's not expensive. I could also run the pump lower than 1200rpm (minimum is 600rpm) but the chart provided my Hayward does not have a GPH figure for running such low speeds with the amount of head that I am running - not sure if that's because they fear it won't prime or if it's not recommended...

 

[ajw22]

Forget turnovers. It is a myth. Pool sanitation is from your chemicals, not turnovers. Run your pump long enough to skim the surface dirt to your satisfaction.

 

[Jimrahbe]

Jeff,

I agree with Allen 100%.. My running 24/7 has nothing to do with "turnovers"...

Jim R.

 

[Oly]

You are going to have to dial in your system by using it and making adjustments. My system only requires skimming and mixing of chemical additions. My pump does not require priming at each start up so I disabled the priming mode. I start my system at 2300 rpm for 2 hours then run at 1100 rpm for 8 hours finally running for 2 hours at 2400 rpm. I only have three settings using the Superflo. I also run my pump during the day as it appears more surface debris accumulates.

 

[thejeff]

Thank you everyone. And yes, I knew some trial and error was in order but it's always most efficient to have a strong starting point and some logic on why things are done certain ways before beginning. I believe I have that now. Thanks again!