How to optimize multiple variables on my VS pump without using calculus!

RogueZhao

Member
Jul 17, 2020
5
NC
I have a new pool (yay!) 20,000gal gunite , plus spa. I have decided to go with the jandy 2.7hp VS pump. And I have jandy Aqua Link. My pool builder has been no help.
I figured I need to calculate the turn over rate for the pool, but my control system uses RPM not GPM. I figure that I should get a full turn over every day but I don’t know how to calculate that.

Now comes the calculus. Optimization of two dependent variables: I want to use the least power to do the most work. I want to minimize run time and minimize RPM to achieve the single turn over. But I’m a biochemist and I’ll be honest I don’t remember how to set up that equation. And I also assume I’m making this more complicated, I highly doubt everyone with a VS pump goes about solving this problem like I am thinking about. I’m assuming there is a simpler way!

so I’m coming to the experts! How doI get the most out of my VS pump? I was promised that it would pay for itself in 2.5 years over a single speed. But then they told me to run it at 3,450rpm 8 hours a day which is full speed and that seems like a waste of a VS pump.

I do not have a salt system, and the pool has been filled for 40 days and the chemicals have stabilized for the most part.
 
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Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
20,165
Bedford, TX
R,

The whole point of having a VS pump is so that you can run at a low RPM and save on the electrical bill... Unless you have a spa, I can't think of any reason to run the pump at full speed (3450).

I have a SWCG and run my pump, 24/7 at about 1200 RPM, most of the time.. Total cost to run the pump is less than $20 bucks a month..

We have people here that run their pumps for only a few hours day... You can run for as little or as much as you want, but you should never run just to try and meet so mythical number.

The turn over myth is based on the idea that your filter is there to prevent algae. The filter is only there to capture the things tat fall into your pool.. Algae is a chemical problem, not a turn over or filter problem.

Thanks,

Jim R.
 

RogueZhao

Member
Jul 17, 2020
5
NC
R,

The whole point of having a VS pump is so that you can run at a low RPM and save on the electrical bill... Unless you have a spa, I can't think of any reason to run the pump at full speed (3450).

I have a SWCG and run my pump, 24/7 at about 1200 RPM, most of the time.. Total cost to run the pump is less than $20 bucks a month..

We have people here that run their pumps for only a few hours day... You can run for as little or as much as you want, but you should never run just to try and meet so mythical number.

The turn over myth is based on the idea that your filter is there to prevent algae. The filter is only there to capture the things tat fall into your pool.. Algae is a chemical problem, not a turn over or filter problem.

Thanks,

Jim R.
Thanks for the feed back! I’ll stop worrying about turn over.

How do you determine the best RPM to use? I assume there is a minimum for my water feature to work so I will have a program set up to run the pump to check that box when I’m wanting that on. But just to check the boxes of skimming and moving chemicals around is half speed considered “low speed”? 1/3 speed?

What are some indicators that let me know I’m getting enough circulation during my filter run time? What would I notice if I was running the pump too slowly?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
34,496
Laughlin, NV
As you are using bleach to chlorinate, your minimum speed would be what it takes to skim the surface. You may also want a speed for Spillover for when you schedule to run the water through the spa. That should be done at least once or twice a day to ensure the FC levels are appropriate in your spa water.
Start at 1200 rpm. See if that sufficiently skims the surface. Run it for 4 or 6 hours per day. See how that looks.