SWG run time calculations assistance

[DAB942]

I asked about the duty cycle. I'm curious as to the answer.

 

[Dave_NJ]

I cranked up my rj-60+ cell output to 100% at 9:30 tonight, FC level was 6.5. Will measure again in the morning and calculate overnight FC gain and tomorrow will shut off the cell to determine daily FC loss.

 

[Dave_NJ]

FC level at 7:00 am after running the cell for 9.5 hours at 100% is 9 so that's a total gain of 2.5 FC.

Pool math app calculated it should have risen by 6.1.

Going to turn off the cell and test the FC level in the late evening to determine daily FC loss.

 

[revitup]

Has anyone else run this simple test? Do all the other SWGs tested produce as advertised?
Something seems seriously wrong with the way Poolmath calculates chlorine production, the way it interprets the SWG published specs, or else the SWG manufacturers are lying.
I have adjusted my SWG production level by trial and error, increasing or decreasing % and run time as required by multiple tests over time. Always thought I was just doing it the hard, non-scientific, way. Looking like that's the only way.

 

[Dave_NJ]

My inclination is the manufacturers list the cell performance based on very specific criteria and operating environments, similar to how car manufacturers list their EPA fuel mileage. Sure you can hit those mpg numbers if you tape the doors shut, run 0w oil, inflate the tires to 100 psi, etc. etc. but real world performance will never reach those figures.

I could be completely wrong (I am very new to team SWCG) but this is my best guess. Some manufactures may list more realistic chlorine generating figures than others, seems like the specs provided by CircuPool for the rj-60+ are very, very optimistic.

It's disappointing if this is the case, I bought my cell based on the specs provided and may have purchased a pentair ic-60 instead but I'm not sure. Right now I have my unit dialed in and it's running at 25% total daily capacity (50% for 12 hours) so it's working in that sense but if I'm only getting the same real life performance as a cell rated for 30k gallons I don't see the benefit of the larger cell. Maybe with more plates it will last longer than a smaller cell even though output is the same??

Regardless, for me I like performing these types of tests so I know what I can expect from my equipment and plan accordingly.

 

[cowboycasey]

The only thing I can say is we have always said SWG do not raise the chlorine level effectively.. They work by keeping the FC at the level they are set to.. If I take my FC level to 12, I can keep it there with my SJ40.. I can almost keep my FC level to SLAM levels (31 for me) with only adding a little extra LC... I have done 2, 2 day SLAMS in the last 3 years...

I am not sure what is happening, I do know with your low CYA the sun is eating your FC during the day and the SWG can not add it back fast enough at night...

My recommendation would be:

1. raise your CYA to recommended levels ( 70 or 80 CYA)
2. raise your chlorine to 8
3. set your SWG to run 8 hours at 100%
4 see if it keeps your FC at 8
5. if it does, sit back, relax, and drink your favorite beverage... If it does not add more run time, if it raises your FC drop your run time...

I do this 3 to 4 times a year to adjust my output

 

[DAB942]

FC level at 7:00 am after running the cell for 9.5 hours at 100% is 9 so that's a total gain of 2.5 FC.

Pool math app calculated it should have risen by 6.1.

Going to turn off the cell and test the FC level in the late evening to determine daily FC loss.

I'm doing the same. Even though I want to know how it works, my main concern is that it does. Knowing how it works will better help me dial it in. In the end, I just need it dialed in.

 

[Brett S]

My inclination is the manufacturers list the cell performance based on very specific criteria and operating environments, similar to how car manufacturers list their EPA fuel mileage. Sure you can hit those mpg numbers if you tape the doors shut, run 0w oil, inflate the tires to 100 psi, etc. etc. but real world performance will never reach those figures.

I think there might be some of that and that’s probably to be expected. I mean the real world is often different than test conditions, and of course the manufacturers want to make their product look better than everyone else’s. But at some point it crosses the line from being overly optimistic to being downright deceptive.

Using your car example, if you bought a car that promised 35mpg you realize that when you are driving it you might only get 30 mpg. Maybe even 25 or 28 it you were driving it particularly hard or in sub optimal conditions. But if you routinely got 13 mpg that just wouldn’t be right.

Along the same lines, I think if the manufacturer is promising an FC rise of 6.1, but you only got 5.5, or even 5 then people wouldn’t really think twice about it. It’s just likely that the real world conditions are different than the test conditions. But only seeing a rise of 2.8 seems way outside of being reasonable.

 

[sbcpool]

FC level at 7:00 am after running the cell for 9.5 hours at 100% is 9 so that's a total gain of 2.5 FC.

Pool math app calculated it should have risen by 6.1.

Going to turn off the cell and test the FC level in the late evening to determine daily FC loss.

That translates to 24 mg/hour. That's very close to what I see, especially given the FC test's margin of error. When I use 25 mL to test for a 0.2 resolution I see 19 mg/hour.

 

[sbcpool]

Circupool did reach out to me. Their position is that the unit should produce 3.1 lbs/day (~60g per hour), but that you can't measure it as FC in the pool. Their position is that the sanitation is taking place in the cell and the return pipe so what exits to the pool is only what's leftover. I can see the logic to that, but it's not something I have verified through testing to be true or false. If that is accurate there should be a point where close to everything that can be oxidized has been and nearly 100% of what's being produced is expelled from the returns. My experiment with draining the spa and filling it with fresh tap water seems to me to discount that hypothesis, but again I have not done specific testing to verify.

I explained my situation with absurd electricity prices and the desire for the shortest run time possible, and that meant I needed enough residual chlorine to keep the pool sanitized in between run times. They were understanding and offered a refund if I can't make it work to my satisfaction, which I appreciated.

Either way, they feel that algae shouldn't be growing as long as there is at least 1 ppm free chlorine in the pool, and that if there is I should look at managing phosphate/nitrates. They requested that I have a local pool store test my water for phosphates/nitrates, which I did. They don't have a nitrate test, but reported my phosphates at 300 ppb. In the interests of troubleshooting I added a product to precipitate the phosphate out and that's where we're at now. Circupool is also investigating what might cause all the bubbles in the returns, which they feel is abnormal.

The conversation was more lengthy, detailed, and nuanced than that. It would be difficult to cover all aspects of what was discussed, but I am doing my best to represent their position accurately.

 

[JamesW]

In my opinion, they need to provide something to show where they got the 3.1 lbs per day number.

Did they just make it up?

Did they verify it somehow?

If a manufacturer makes any sort of claim about their product, they have to have a reasonable good faith basis for the claim.

If anyone asks, they should be ready, willing and able to verify the claim.

If they can't verify the claim, they should cease making the claim.

 

[mas985]

Has anyone else run this simple test? Do all the other SWGs tested produce as advertised?

The Hayward T-15 is pretty close to advertised. I have tested over a wide range of salt and temperatures and it is fairly linear with amps. Production ranges from 1.14 lbs/day up to 1.6 lbs/day. Average of all test results was 1.43 lbs/day which is very close to the spec of 1.45 lbs/day. The average production coefficient is 0.24 lbs/amp/day.

 

[DAB942]

I might have to kind of start over with re-balancing my chems. I might have dropped chlorine level a couple weeks ago where the SWG just can't "catch up" fast enough.

 

[laprjns]

I've got an Inyo Pools Crystal Pure 60,000, a Hayward clone which is rated at 3.18 lbs per day. In my 30K pool running it at 100% it should yield about 0.5 ppm per hour. Last night I ran it for four hours at 100%. It started with FC at 7.4 ppm (37 drops). After two hours FC was up to 8.6 ppm (43 drops) and after another two hours (4 hours total) it was at 9.4 ppm, (47 drops). So base on this, it look like my SWG is producing at around it rated production of 6.18lbs 3.18 lbs per day.

Note that when generating, the voltage is at 21.8 and current is 6.4 amps. Voltage when not generating is 28.5

(Edited for clarity; I'm using a 25ml water sample which then has each drop of the reagent equal to 0.2 ppm )
(2nd Edit - typo 6.18 should be 3.18)

 

[Cavmedic]

I've got an Inyo Pools Crystal Pure 60,000, a Hayward clone which is rated at 3.18 lbs per day. In my 30K pool running it at 100% it should yield about 0.5 ppm per hour. Last night I ran it for four hours at 100%. It started with FC at 7.4 ppm (37 drops). After two hours FC was up to 8.6 ppm (43 drops) and after another two hours (4 hours total) it was at 9.4 ppm, (47 drops). So base on this, it look like my SWG is producing at around it rated production of 6.18lbs per day.

Note that when generating, the voltage is at 21.8 and current is 6.4 amps. Voltage when not generating is 28.5

FC should be 18.5. Its 37 drops x .5 or 37/2.
Same with 43 drops x .5 = 21.5 FC and 47 drops x .5 = 23.5 FC


Unless I have lost my mind which is possible. Are you using a different method than FAS-DPD Chlorine Test - Trouble Free Pool

 

[HeyEng]

I think there might be some of that and that’s probably to be expected. I mean the real world is often different than test conditions, and of course the manufacturers want to make their product look better than everyone else’s. But at some point it crosses the line from being overly optimistic to being downright deceptive.

Using your car example, if you bought a car that promised 35mpg you realize that when you are driving it you might only get 30 mpg. Maybe even 25 or 28 it you were driving it particularly hard or in sub optimal conditions. But if you routinely got 13 mpg that just wouldn’t be right.

Along the same lines, I think if the manufacturer is promising an FC rise of 6.1, but you only got 5.5, or even 5 then people wouldn’t really think twice about it. It’s just likely that the real world conditions are different than the test conditions. But only seeing a rise of 2.8 seems way outside of being reasonable.

Almost sounds like the Circupool folks are taking "puffery" a bit far (here's a good article about puffery). As a bonus for readers interested in puffery in adverting, do a quick search for "Carbolic Smoke Ball." Be warned that there is a fair amount of legalese, so that may not be as exciting to some folks.

I will do the "simple test" described above tonight to see how high it will push my FC @ 100%. Mine is still a few weeks old, so I am still dialing it in. Things to be fairly level, then we will have a couple of cloudy/cooler days and the FC shoots up a few more PPM and so I dial it back. I will report back tomorrow my findings.

 

[laprjns]

Are you using a different method than FAS-DPD Chlorine Test - Trouble Free Pool

Yes, I'm using a 25ml water sample which then has each drop of the reagent equal to 0.2 ppm

 

[JamesW]

A claim of specific performance that is measurable is not "puffery".

A claim that a unit can produce 3.1 lbs per day is not subject to opinion.

The unit can either do it or it can't.

If a seller makes such a claim, they have to have something to support the claim.

It's like a real estate agent saying that a house is "charming" vs. saying that the countertop is Carrara marble.

"Charming" is an opinion, the countertop should be provable and it's not an opinion.

 

[Brett S]

I've got an Inyo Pools Crystal Pure 60,000, a Hayward clone which is rated at 3.18 lbs per day. In my 30K pool running it at 100% it should yield about 0.5 ppm per hour. Last night I ran it for four hours at 100%. It started with FC at 7.4 ppm (37 drops). After two hours FC was up to 8.6 ppm (43 drops) and after another two hours (4 hours total) it was at 9.4 ppm, (47 drops). So base on this, it look like my SWG is producing at around it rated production of 6.18lbs per day.

Note that when generating, the voltage is at 21.8 and current is 6.4 amps. Voltage when not generating is 28.5

(Edited for clarity; I'm using a 25ml water sample which then has each drop of the reagent equal to 0.2 ppm )

So this is very interesting to me. This is another 60,000G rated SWG that is rated for around 3+ Lbs per day. The voltage and amperage is close to what @sbcpool is reporting for his 60,000G rated SWG that’s also rated for around 3+ lbs per day. However @sbcpool is reporting a FC rise of much less in his pool.

This seems to suggest that it is possible to get that much chlorine generation from 22V and 6.4 amps.

 

[JamesW]

So base on this, it look like my SWG is producing at around it rated production of 6.18lbs per day.

Now it's producing more than 6 lbs per day?