Variable Pump Questions

[Marines75]

Good Morning! I just got a Pentair Variable Speed pump. I have a SWG and Heater, what should my settings be so I can be most efficient with the SWG and Heater. I am new to the variable pumps and kind of lost.

Also, When you backwash, do you wait for the pump to finish priming or can you backwash while it is priming. It seems that I am losing some sand from my filter when I back wash. Is the setting too high?

Thank you so much for all your guys help. I really appreciate it.

 

[midlifecrisis]

I am new to pools in general, but I run my pump at 1200 RPM 24/7 and have it programmed to increase the RPM to 1400 when the heat pump or chiller calls to get sufficient flow and return to 1200 when done. The 1200 provides enough flow for the SWG and good skimming and still only costs me about $15 per month!

I can’t speak to the backwash question, sorry.

 

[PoolStored]

Backwash your filter. (note your pump pressure so that you know your baseline). Turn on your SWG and you heater so both are running. Reduce your pump rpm until the heater turns off or the SWG turns off due to low flow. Note that rpm. Add 100 RPM and then multiply by 1.2. This is your minimum RPM (more later). The 100 is to keep the SWCG on. The .2% increase is to accommodate a dirty filter and still allow the SWG and heater to run.

Backwash your filter when pressure rises 25% from baseline clean filter. If you run above min RPM and do backwash with 25% rise, your SWG and heater should always work.

You could run lower RPM that the minimum we calculated, but you want to backwash more often than 25% rise.

I would run 24/7 at the calculated minimum for chlorinating and heating. Run for a couple days. If you don't like the skimming, then choose a period of time for the pump to run higher, maybe 2000-2200 for a period of time. My min is 1750, costs me about 24$ a month to run the pump and my skimming is just fine.

Hope that helps...

 

[Homebrewale]

You didn't say what type of heater. On my last pool, I had a heat pump. The heat pump needed a higher flow rate than the SWG. Doing the experiment as PoolStored described, I lowered the pump speed to where the heat pump shut off and then kept lowering it to when the SWG shut off. From there, I set the pump speed between the shutoff speeds between the SWG and heat pump so at night, the SWG would run but the heat pump would not.

 

[PoolStored]

You didn't say what type of heater. On my last pool, I had a heat pump. The heat pump needed a higher flow rate than the SWG. Doing the experiment as PoolStored described, I lowered the pump speed to where the heat pump shut off and then kept lowering it to when the SWG shut off. From there, I set the pump speed between the shutoff speeds between the SWG and heat pump so at night, the SWG would run but the heat pump would not.

And, you ran higher RPM during the day, above heat pump minimum...

 

[Homebrewale]

And, you ran higher RPM during the day, above heat pump minimum...

I did but it wasn't straightforward. Through my experiments, I found that the heat pump needed a higher pump RPM to start than to stay running. I've tossed the data so I can't give you exact numbers. So I'll make some up for illustration. When lowering the RPM of the pump to find when the heat pump shut off, it shut off at 1000 RPM when the sand filter was clean. Then when starting at a low RPM and increasing it, I found the heat pump didn't turn on until 1100 RPM.

My solution was to program the pump to increase to around 1800 RPM in the morning around 8:00am for 30 minutes to help skim anything that fell on the pool surface overnight. Then lower it to a speed where I could keep both the SWG and heat pump on and save as much electricity as I could. Then lower the RPM at sunset to a point where the heat pump would not operate. One nice thing about the Hayward VSP I had is that I could set 8 programmed speeds every day.

I only did this in late spring and early fall. In the summer months, I turned off the heat pump since it was not needed.