Pentair Intelliflo VSF - RPM speed

[Barkyman]

I have been reading a lot of the questions and answers on run time and speed for VSP. I am a new pool owner, 27.5k gallons, 3HP Intelliflo VSF and a FNS Plus DE filter and SWG.

I currently run my pump for 12 hours at 2.8k RPM which turns my pool over 1.5times. Should I run my pump at 1.4k RPM for 24 hours? How could I calculate the cost difference. Still trying to figure out the best runtime and speed at the lowest cost.

 

[mknauss]

You run the pump for a reason, not for the mythical 'turnover'.
You have a SWCG, so first is to run the pump long enough at the minimum rpm needed to operate the SWCG and create the chlorine you need.
Next is to run long enough to skim the surface to your liking. If the rpm for the SWCG is too low, raise it some to achieve skimming. But in most cases, if things are set properly, the pool should skim at the lower rpm.

Fill out your signature so we know what equipment, etc you have. See Create Your Signature - Further Reading

 

[BDY]

Watts and rpm are not linear but almost exponential …. Higher rpm = much higher watts used

I have a 3hp intelliflo and run 24/7 at low speed (a few hundred rpm over the flow switch minimum for my swg - 1000 rpm iirc) for 14$ a month… (and that includes kicking it up to 2400 rpm once a day for 45 min). At low speed it’s 70 watts an hour. At 2400 rpm it’s 1200 watts!

It lets me continuously filter as well as set the SWG lower and make chlorine round the clock.

Many SWG/VSP members run 24/7 - I think @Newdude has done a few posts on the power and rpm Relationship. Marrying a SWG and a VSP makes it a almost a no brainer to run constantly at lower rpm and reap the benefits

 

[Jimrahbe]

Marrying a SWG and a VSP makes it a almost a no brainer to run constantly at lower rpm and reap the benefits

 

[Barkyman]

Great. Thank You. Maybe I will try to run 24 hours, half the speed and half the SWG output. Then test to make sure my chlorine is still maintaining the same level. I'll also do the math for the energy $ at both RPM as well.

 

[BDY]

A good test - lower the rpm
Until the flow error on your cell goes on (however it indicates low flow) then raise the rpm a few hundred. That’s your minimum low speed assuming you have a cartridge filter

(If you have sand or DE add a few more hundred rpm on top of that as flow will reduce when dirty and your “floor” rpm becomes variable)

 

[Newdude]

I think @Newdude has done a few posts on the power and rpm Relationship.

I leave the nitty gritty of power curves to @mas985 and @JamesW. But I have seen my own many times range from 35W at 700 RPMs to 1800W at 3000 RPMs.

In the lower RPM range, going up 100 doesn't make much difference in wattage. Those last few clicks are doozeys though.

Also, huge fan of 24/7 low RPM. Hot.

 

[BDY]

Ps - you can model SWG effects with pump
Time and pool size in Pool Math

Go to effects of adding and select “SWG” - fill in details of pool and SWG and away you go!

( for example the rated output of a IC40 is 1.4 pounds or day. )

 

[Jimrahbe]

B-Man,

The myth that you have to turnover your pool water x times a day is based upon the idea that the filter is there to remove algae from your water. Well, that is not what your filter is for. Your filter is simply there to capture all the junk that falls into your pool each day. By the time the filter starts to capture algae, it is way too late, as you have already lost the algae war... Algae is a chemical issue not a mechanical issue.

I run my IntelliFlo 24/7 as I like to make a little chlorine all the time, and I like to skim all the time. I also like the look of my pool when there is a little motion to the water, instead of something that looks 'dead'.

Thanks,

Jim R.

 

[Barkyman]

Great thanks. Putting alge aside wouldn't it be ideal to cycle through your pool volume at least once a day to know your getting most the Crud out of the water each day?

Maybe I am missing the logic.

I have noticed I don't get any real swirl in my 3 skimmers under an RPM speed of 2.6k on my VSP. My inlaw has a single speed pump and he sees the swirl in his skimmers. But I guess there is a big difference and using a VSP is running at lower RPM is much more cost efficient versus a single speed.

 

[Newdude]

Putting alge aside wouldn't it be ideal to cycle through your pool volume at least once a day to know your getting most the Crud out of the water each day?

Your falling/blowing yard debris determines that, which varies tremendously throughout the season. You might need lots of filtering in the spring/fall, and very little mid season.

Or it varies from one neighbor with trees, upwind of the neighbor next to them. Or with a screened enclosure. Or in the dessert. Or 100 other variables.

Your pool needs what your pool needs, when it needs it. The industry just picked a number which should satisfy most people's needs, as a blanket statement. If you actually need half a turnover everyday this week, and they had you do 3, they weren't wrong, but they weren't right either.

I have noticed I don't get any real swirl in my 3 skimmers under an RPM speed of 2.6k on my VSP

That should push alot of flow though the filter. Are there any valves you can adjust to direct more flow through the skimmers ? With main drains, I need 90% or more to the skimmers or they lose oomph.

My inlaw has a single speed pump and he sees the swirl in his skimmers

Again, apples to oranges. Pool A with one skimmer and a SS pump will behave differently than pool B with 3 skimmers/returns and a VS pump running lower RPMs. (I have no clue what either of you have, just stating the logic)

 

[Jimrahbe]

Putting alge aside wouldn't it be ideal to cycle through your pool volume at least once a day to know your getting most the Crud out of the water each day?

B-Man,

Not really. Most things that fall into your pool either float, or the sink to the bottom, they don't tend to stay in between. The stuff that floats is captured by the skimmers and the stuff that sinks is picked up by a cleaner.

And since the water in the pool is continually mixing it would be impossible to ensure that only 'new' water passed through the filter...

Just to be clear. We are not against people turning over their pool water 50 times a day, if that is what they want to do.. We are against the idea that you MUST turnover your water x times a day. Your case is a good example... you were trying to run your pump at a speed based upon a myth. We are just trying to say you don't need to do that, so that you have the option to run the best speed for you and your pool.

It is true, that you won't see a swirling vortex in your skimmer when using a VS pump at low RPMs.. But it does not matter, as the 'vortex' is not what causes the skimmer to work. The weir door is what makes the skimmer... (wait for it...) Skim. The whole purpose of the weir door is to only allow the surface water to enter the skimmer. Hence the name "skimmer". I use hairnets in my skimmers and I can guarantee that skimmers still work great even at low speeds, they just do not look the same as when using a single speed pump.

Hairnets 1.jpg

• Jimrahbe
• Apr 1, 2023

Thanks,

Jim R.

 

[BDY]

At 1000 rpm I’m pushing 20 GPm. At 24/7 that’s 28k gallons which is 3x my pool size. Do the math - I think you’ll be surprised how much volume is pumped at low speed by the bigger VSP pumps.

 

[Barkyman]

Appreciate the feedback - very helpful. I'll have see how I can adjust to be more efficient with the pump and speeds.