Variable speed pump schedule (again)

[joalepins]

Hi guys,

Yes another question about VS pump schedule.

Even after watching pretty much all clips on YT, I can’t figure out the best schedule for my pump.

Pump is a 11k gallons, 14x26 with a steady slope (beach slope).

Pentair superflo VS

Hayward salt system.

Nirvana 75k heat pump

I have a flow meter and logged all my GPM :

1700 rpm = 30gpm

1800 = 31 gpm

1900 = 32-33 gpm (OK for heat pump)

2000 = 35 gpm

2100 = 36-37 gpm

2200 = 38-39 gpm

2300 = 39-40 gpm

2400 = 40 gpm

2500 = 41 gpm

2600 = 42 gpm

2700 = 44-44 gpm

2800 = 45-46 gpm

2900 = 47 gpm

3000 = 49 gpm

3100 = 50 gpm

3200 = 51 gpm

3300 = 52-53 gpm

3400 = 54 gpm

3450 = 55 gpm

I live in Quebec (Canada) so nights are still on the cold side (around 10-15C). Days around 20-25C and around 30C during summer.

My heat pump kicks in at about 1900 RPM but not always, sometimes need to boost up to 2100-2200 rpm to get it started.

From what I understand I need to turn at least one time the water per day.

I have kids that are mainly using the pool.

When I want to heat the pump, I use the quick clean button set to 2500 rpm for 24h that I set manually everyday when heating.

Where do I start ?

Best to run the pump during the day at low speed or mid speed ?

Better to run low/mid/high speed at night ?

Thx for all the help you can provide

Jo

 

[Darin]

Run it at the lowest rpm that will skimmers will work at ($$$ electical savings). Maybe start at 1000 rpm's. Turn it up when you need the heat pump and wide open when you manual vac. Make sure to run it low when your electrical rates ramp up which is usually in the afternoon. Here it is 4pm - 9 pm.
You only need your skimmers to work. Don't worry about any other variable exept heat pump flow and SWG flow which i assume you do not have.

 

[Jimrahbe]

From what I understand I need to turn at least one time the water per day.

Joal,

The idea that you have to turnover X amount of water per day is just Bull Feathers. Just not true.

Chemicals keep your pool sanitized and clear, not the number of times water passes through the filter.

We don't care if you want to turn over your pool water 10 times a day, we just want you to run your pump for a reason, not for some myth.

Some of the reasons to run a pump are to generate the chlorine your pool needs if you have a SWCG or a chlorine tab feeder. You also want to skim the surface water.

Worrying about GPM is just a waste of time in most cases.

Thanks,

Jim R.

 

[joalepins]

Here in Quebec, we don’t have different rates during the day, always the same. I think I have a flow switch on the salt system … If that’s what you were asking ! I’m looking to be more precise on the schedule to max out savings while having everything working fine. Also, I’ve read that always running the pump at a low rpm isnt good. Pretty much what you don’t want to do with a variable speed pump … I’m no expert though !

 

[Jimrahbe]

joal,

I am not sure why anyone would say not to run a VS pump 24/7? And running at a low RPM is the whole purpose of having a VS pump.

Two trains of thought... One says running 24/7 will shorten the bearing life. The other says starting a stopping the pump several times of day is much more damaging to the pump then running 24/7.

I am not sure the pump cares one way or the other.

I have three pools that all have 3 HP IntelliFlo pumps. They all run 24/7, mostly at about 1200 RPM. That is the speed I need for my SWCGs to run and that keeps my pools skimmed.

One pump has been running 24/7 for over 10 years, one is over 8 years old, and the other is about 7 years old. They all work today almost like they did when new. I'm running them this way because it makes sense for me. But I am also curious to see how long they will last. They could all die tomorrow, or last another 10 years, but either way, I'll be sure to let everyone here know the status.

Right now, I'm only hoping that whenever they die, that it is after the shortage of IntelliFlo pumps is over.

The slower you can run and still get the job done, the less it costs for the electricity and the quieter the pumps will be.

Thanks,

Jim R.

 

[joalepins]

joal,

I am not sure why anyone would say not to run a VS pump 24/7? And running at a low RPM is the whole purpose of having a VS pump.

Two trains of thought... One says running 24/7 will shorten the bearing life. The other says starting a stopping the pump several times of day is much more damaging to the pump then running 24/7.

I am not sure the pump cares one way or the other.

I have three pools that all have 3 HP IntelliFlo pumps. They all run 24/7, mostly at about 1200 RPM. That is the speed I need for my SWCGs to run and that keeps my pools skimmed.

One pump has been running 24/7 for over 10 years, one is over 8 years old, and the other is about 7 years old. They all work today almost like they did when new. I'm running them this way because it makes sense for me. But I am also curious to see how long they will last. They could all die tomorrow, or last another 10 years, but either way, I'll be sure to let everyone here know the status.

Right now, I'm only hoping that whenever they die, that it is after the shortage of IntelliFlo pumps is over.

The slower you can run and still get the job done, the less it costs for the electricity and the quieter the pumps will be.

Thanks,

Jim R.

And how do you know if you move enough water ? If I have debris in the skimmer then enough movement ? So basically, just run the pump at let’s say 1500 rpm and boost it up when heater is working or in super chlorinate ?

And also, I’m not saying to stop the pump during the day. Just run it at different speeds throughout the day.

The reason why they put 3 settings buttons on the pump no ?

 

[Jimrahbe]

Joel,

You should run the pump for a reason. Each reason might have a different speed. Like one speed to run a salt cell, another to run the heater, one for the skimmer or suction vac, one for a waterfall, etc...

I don't think they put the buttons there because you have to run the pump at different speeds, but rather so that you can run the pump at whatever speed is needed for the function that you are trying to do.

I never use super chlorinate, but if I did, pump speed would not make any difference. As long at the flow switch closes, a faster speed does not produce any additional chlorine.

Anyway, these are just my opinions as to what I think is the best way to run the pump. You should run your pump the way that works best for you.

The only way I know to do that is to experiment with the speeds and see what works for you and your pool.

Thanks,

Jim R.

 

[M T]

It is good you have a flow meter. That's one accessory I'd like to add. I had to work from filter PSI gauge to get the head of water, and then to use that to look up flow rate from vendor's performance graphs. (I get a back-of-the envelope number, not very accurate.) I also recorded the watts at each of the RPM settings so I could look at energy efficiency.

It would be interesting to see your GPM/watts for the range of RPM. For my 110V pump and the filters at the time I took measurements, it appears that 3000 RPM is 23% more efficient (Gallons/watt) than 3450 RPM, 2400 RPM is 38% more efficient than 3450, 1400 RPM is 51% more efficient than 3450. So I rarely use 3450 RPM. YMMV.

Remember that the flow will depend upon how clean your filters are. The numbers you got are good for the present state of your filter.

I find it odd to see one poster's basing pump time/rate on skimming. In my pool, I can adjust the skimmer to get anywhere from 0 to 100% of the pump's suction. Skimming is not even relevant for when the pool is covered and I don't use it that much when the pool is uncovered. The only time I really require skimming is when there is a pollen layer on the pool.

What is working for me is to run the pump for an hour at a higher speed (3000 RPM. I use 9-10AM as an hour when the electrical grid isn't stressed and no one's going to complain about the noise.) That's to make sure there is a good current in the pool to mix the water/chemicals in the nooks and crannies. (If I could, I'd probably rather do four 15-minute high speed runs throughout the day.) Algae doesn't grow out in the middle of the water -- it survives best where the flow is the least. (15 minutes seems about right for the pool current to build to full strength but I've never measured it. The total of an hour is ad hoc and is an easy unit to deal with.)

I have the pump off for 4 hours of the day (4-8PM) when the electric company wants us to minimize usage (and when the rates are higher).
The rest of the time, I've got it set to a low speed -- 1000 RPM. That keeps the water mixed (mixing heat from the water under the cover, keeping the chemicals from becoming stratified) and will help filter out anything stirred up during the higher speed run. 32% of the electricity use is during that one high-speed hour but only 27% of the filtration (water flow) is then. Overall, I'm filtering a bit more than the pool volume per day.

My pump allows me to set duration of 3 periods per day. For me, the pump day starts at 8PM. 13 hours at 1000 RPM overnight, 1 hour at 3000 RPM (9AM-10AM), 6 hours of 1000 RPM during the day. The remaining 4 hours it is off. A bit under 4 kwh ($1.50) for the day.

If I were a salty-pool guy, I'd need to make sure that minimum speed was enough to keep the SWG operating.
If I were heating my pool, I'd have to have enough pretty fast speed of the pump to keep the heater on enough time to be effective.
I try to check the chemistry in the morning, and add anything I need during that high-speed hour. But if I do it later, I just punch the button for that hour and I get an hour's worth of good mixing (and heating, if it's on).

The traditional advice for single-speed pumps is to clean your filter when the pump pressure goes up 10psi. With a variable-speed pump, which speed should one measure that at? If you run your pump usually at a low speed, then 10 psi (= 23 feet of water) differential may not be even possible. (For instance, see the current performance graph for Pentair SuperMax VS. Btw, my 2014 brochure for my version has different curves, and I've seen a 3rd set of curves for this same model.) I chose 3000 RPM as the speed at which I check the PSI to determine when to clean the filter. With a flow meter, I'd guess a rule of thumb would be when the flow (at your standard speed) drops to half of the clean filter rate.

Note: The pump is 5 feet from our bedroom window and doesn't bother us at 3000 RPM at night. But it is also 20 feet from a neighbor's bedroom window, so I don't run it that high. 3450 RPM is quite a bit louder. 2400 RPM would be plenty quiet.

 

[Darin]

Joelpins,
I have 60 different setting on my pump as i can run it by hertz. I only use two of them. Slow (20hz) and wide open (60 hz) for vacuuming. I do not have a swg but if i did i would figure out what flow i needed and go from there. I do not see any reason to fluctuate speeds, after all you only need you skimmers to work for however long your pool needs. It is up to you to decide. Remember your pump does not care about starting and stopping but you motor does. You live in the Midwest like me so you might start it 120 times a year at once a day. That times 15 years is not lot but more that my 20 times a year.
When i add chlorine or muratic acid its at the return so it quickly finds equal concentration in the pool. My pool is only 8 foot deep so i do not have a thermocline.
My electrical rate doubles from 0.08 to 0.16 during peak but i still run it slow. I do not have any automation. Then again i have not SLAMMed during the swim season in three years. I figure that the extra bleach and time to SLAM is is greater keeping track of my chlorine level and the electrical run time during peak hours. (100 days of swimming * 5 hours peak * $0.08 = $40 of peak electricity).
The important thing is to keep track of your chlorine level. If you do that you won't have to worry about algae. because it wont have a chance whether you run you pump for 6 hours a day fast or 24 hours a day slow.