SWG limit chlorine output

pgjohnson

Well-known member
Jun 21, 2015
102
Australia
Just wanting to know a basic concept.

Is it possible for a SWG to show its outputting chlorine at 100% but that is not really happening?

I have the Viron V35 and pool approximately 45000L. According to pool math it should increase at approximately 0.8ppm every hour. When running for 8 hours (should increase 6.4ppm) but after a few consecutive days of testing I find the chlorine level can sometimes hold or drop about 0.5ppm. As below, if I am losing about 5ppm, I would expect an increase if running for 8 hours.

My chlorinator is sized for a 80000L pool so would not expect to have to run for 8h at full and also seem to remember I have not done it in the past.

Interestingly something else I tried seemed strange. I ran pump after dark for 3 hours and had no change in chlorine level (after running for 2x4 hours during the day), measured before and after 3 hour run? During this 3 hour run I monitored SWG which showed producing at 100% and could visibly see mist/gases well in cell housing.

Diagnosis done so far:
  • Passed OCLT
  • New cell, 1 month old
  • Measured chlorine loss for the day (added no chlorine for a day moved from 9.5ppm to 4.5ppm) - 5ppm
Thinking of sending unit and cell for testing at repair shop but just not sure a unit showing producing at 100% with a new cell, they would be able to detect anything.

Any help appreciated.
 
Just wanting to know a basic concept.

Is it possible for a SWG to show its outputting chlorine at 100% but that is not really happening?

I have the Viron V35 and pool approximately 45000L. According to pool math it should increase at approximately 0.8ppm every hour. When running for 8 hours (should increase 6.4ppm) but after a few consecutive days of testing I find the chlorine level can sometimes hold or drop about 0.5ppm. As below, if I am losing about 5ppm, I would expect an increase if running for 8 hours.

My chlorinator is sized for a 80000L pool so would not expect to have to run for 8h at full and also seem to remember I have not done it in the past.

Interestingly something else I tried seemed strange. I ran pump after dark for 3 hours and had no change in chlorine level (after running for 2x4 hours during the day), measured before and after 3 hour run? During this 3 hour run I monitored SWG which showed producing at 100% and could visibly see mist/gases well in cell housing.

Diagnosis done so far:
  • Passed OCLT
  • New cell, 1 month old
  • Measured chlorine loss for the day (added no chlorine for a day moved from 9.5ppm to 4.5ppm) - 5ppm
Thinking of sending unit and cell for testing at repair shop but just not sure a unit showing producing at 100% with a new cell, they would be able to detect anything.

Any help appreciated.
It will depend on your CYA level.
 
CYA at 50%.

But not sure CYA should factor here if I measured a loss of 5ppm per day and my chlorinator should generate 6.4?
Even at 0 CYA I should still increase?

But I am sure I'm missing something :)
FC degrades rapidly without CYA so it does matter quite a lot. Try increasing it a bit if you are sure there is no algae. The output of the machines tends to be exaggerated.

But if you measure a loss of 5ppm during the day that points to something eating it. How are you testing the water? Testing for only a 3 hour interval may not be giving the duty cycle of the machine enough time. Try it for 24 hours and make sure the pump runs the entire 24 hours and doesn’t shut off.
 
Understand FC degrades worse with lower CYA but have measured the daily CYA loss.

Actually another interesting fact, if I run at 100%, after 8/9 hours the SWG indicates high salt and shuts off the cell production. This only happens always after about 8 hours of continuously running at 100%. Salt is definitely not high, around 3600 ppm.
 
Understand FC degrades worse with lower CYA but have measured the daily CYA loss.

Actually another interesting fact, if I run at 100%, after 8/9 hours the SWG indicates high salt and shuts off the cell production. This only happens always after about 8 hours of continuously running at 100%. Salt is definitely not high, around 3600 ppm.
That sounds like the cell may have buildup on it. Is it possible to inspect it? 3600ppm sounds kinda low for Australia. Assuming that was measured with a reliable kit and you’re not trusting the reading on the SWCG display right?
 
Salt not measured by swg. Have always run salt around this level, running higher than 4500 usually registers high salt and shuts off cell. Also cell less than a month old and looks clean
Did you say how you were measuring the chlorine output? Your signature doesn’t show a kit.
 
Running a cell at 100% continuously is the best way to kill a cell.

We recommend that your cell should be sized 2x your pool size, so you never have to run 100%.

Cell ratings in marketing materials and specs, can be and are typically, overly optimistic
 

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FAS kit from clear choice labs
I suppose one way you could rule out sunlight/heat consuming chlorine is to run the pool for 24 hours with the SWCG off and then do the same thing with th me SWCG on and compare the difference. If you don’t gain any on the second try, there would seem to be a cell issue.
 
Yeah. SWG rated for 80000 to 120000 but 80 in tropical. So definitely 80 in our heat conditions.

Just sure worked better in past and according to poolmath should cope easily.

Unfortunately seems some issue with controller as Darn cell off after about 8 hours indicating high salt when the salt level is actually low.

Just not sure if a repair shop could diagnose anything but guess cheap enough to check. Just trying to determine if system can show working at 100% but not producing at 100% with a new cell.
 
Yeah. SWG rated for 80000 to 120000 but 80 in tropical. So definitely 80 in our heat conditions.

Just sure worked better in past and according to poolmath should cope easily.

Unfortunately seems some issue with controller as Darn cell off after about 8 hours indicating high salt when the salt level is actually low.

Just not sure if a repair shop could diagnose anything but guess cheap enough to check. Just trying to determine if system can show working at 100% but not producing at 100% with a new cell.
The thing is on and producing or it’s not. It’s not smart enough to check its chlorine output to tell you if it’s producing as much as it’s supposed to. Most people with your problem actually have algae consuming the chlorine so having someone look at your test result log and your OCLT results would be free and possibly help confirm a hardware problem.
 
You have too many variables, and too short of an evaluation period, to give much meaningful information.
Ideally, you would have run a 24 hr test when it was brand new. And now, with the pool as close to exactly the same as it was then (salt, CYA, temp, no algae, etc.) you run it again to compare.
I suspect sending for repair may be less than hoped for - it depends on whether they will actually test by using a standardized water solution coupled with volt/amp tests on the cell. More likely a visual check, and a quick electrical continuity check. Nothing detailed about efficiency.
Me? I'd just run at whatever strength and time is needed to maintain the desired CL level, and not worry about theocraticals. If it needs to be ramped up more and more over time, then considering replacement may be in the cards.
 
To test immediate output you can use an empty water bottle at the mouth of a return jet and let it fill then squeeze 2-3 times so you have the return water almost 100% captured then test if its more chlorinated then the rest of the pool water. Make sure the cell is at 100% to be guaranteed it's in the producing mode.
 
Yeah have tested return jets and get about a 1ppm reading higher than pool.

Definitely producing, guess just trying to get head around what the output setting on the chlorinator does. So when set to 100% there is more misty gas showing in cell than when set to 20% but is 100% actually producing at 100% (presuming cell working perfectly) or could wire/other issues say its at 100% but really at 80/90%. Reason I am questioning this is I ran for 3 hours at 100% after dark and had no change in chlorine level (misty gases visible at all times in cell).

Anyway thanks for all the help, will just try think of some more ways to test.
 
Yeah have tested return jets and get about a 1ppm reading higher than pool.

Definitely producing, guess just trying to get head around what the output setting on the chlorinator does. So when set to 100% there is more misty gas showing in cell than when set to 20% but is 100% actually producing at 100% (presuming cell working perfectly) or could wire/other issues say its at 100% but really at 80/90%. Reason I am questioning this is I ran for 3 hours at 100% after dark and had no change in chlorine level (misty gases visible at all times in cell).

Anyway thanks for all the help, will just try think of some more ways to test.
Unless you have a unique system, when set to 50%, the device produces chlorine for 50% of the time its on. So for your 3 hour period, it would only be making chlorine for 1.5hours. If it’s set to 100% then it’s making chlorine 100% of that 3 hours. That’s what the setting on the device does.

There are supposedly some systems that alter the amount of chlorine made depending on the power setting you specify but I’m not familiar with how those work.
 
Think it might be a power thing, can definitely notice less misty/gases if I lower the setting from 100%. Setting is for 0 - 8 levels with 8 maximum.

This might confirm above:
 
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