SWG with new variable speed pump

[swahl]

I wasn't sure what forum area to post this in, but since the SWG is my first concern, I started here.

My pump would hum but not spin as I attempted to open my pool this year, and I got a late start anyway as we've been busy and the warm weather's coming. Time being of the essence, I called my pool guy (he installed the pool ~12 years ago) and had him replace the pump. He put in a Pentair Superflow VS. Had I time to read ahead I'd have probably chosen a two-speed instead, but that's water under the bridge now.

The rest of my system includes an Aqua Logic SWG + controller, one of the earlier models. Right now it's just hooked in place of the former single speed pump; if I read the manual correctly, as long as it doesn't go 24 hours without power, it'll run on whatever its internal schedule calls for when the Aqua Logic controller turns the pump power on. I might eventually wish to order the pump's control cable and let the automation have more control... someday.

But for now, I want to understand: what's the relationship between SWG output and pump speed? Assuming I don't go below the minimum flow level for the SWG to kick in, does it create approximately the same amount of chlorine, no matter the flow? So at a slower speed, the returns would have a higher concentration of chlorine, that would hopefully then "mix" in the pool, so same runtime approximately equals the same amount of chlorine in the pool, regardless of speed?

Thanks!

 

[RobbieH]

The pump speed does not affect SWG output. BUT, if the pump is set TOO slow, the flow sensor may think there is no flow and shut the generator off.

I run my pump at about 1400 rpm, and let it run 24 hours. I did the math in a spreadsheet and found this uses the least electricity.

 

[JoyfulNoise]

You are correct. For all practical purposes, the SWG output is independent of flow rate as long as you are above the minimum flow rate for your brand of SWG.

 

[swahl]

Thank you both!

Next question (although I *really* may be in the wrong section of the forum now): would it be the same idea for the pool heater? Assuming you are above it's minimum flow, at lower flow rates you get hotter water at the return jet, but same amount of total heat added to the pool as a whole?

 

[ping]

Here is a link to a thread that goes over this, Heating with a variable speed pump.

You can use the search function to find other threads with the same topic.

 

[pooldv]

No, you need higher flow rate to get the most from your heater. The owners manual should give some reference points on entering and leaving water temps. My heat pump recommends a flow rate to achieve a 2°C increase in water temp.

 

[swahl]

Thanks, both of you! Although I have Aqua Logic, the new pump (with built-in timer) was installed with power being the only connection to the controller (so the schedule in the pump is the only thing that can select the current speed). I may need to order the remote control cable for the pump to see if I can increase the pump speed when the heater is on. For now, though, I'll just use a faster pump speed while I'm in the heating portions of the season.

Back on topic for the SWG area: my AquaLogic is now displaying CELL POWER ERROR. At first I thought it might be related to running at a slower speed, but after cranking up the pump, I'm quite sure it's not. I've done *plenty* of searches on this topic now, tried resetting it a couple of times, diluted my salt concentration a bit so it's now in the middle of the recommended range rather than on the high side, no change.

This is different from the "NO CELL POWER" error, which I had previously fixed (a couple of years ago) by re-soldering the connection on the circuit board. So, now I've got a replacement GLX-PCB-MAIN (main circuit board) ordered and on its way. I'm using other chlorination methods in the meantime.