SWG run time calculations assistance

[sbcpool]

In order to get a better handle on chlorine generation/replacement I guess the next step would be to raise FC level to around 10 in the morning, keep the SWCG off for the day and test in the evening to determine my chlorine loss and that would tell me how much I need to replace during the day to maintain levels. Is this correct? If so I will do this tomorrow and report back.

Right. The opposite of a OCLT. Just remember it's a proportion, not an absolute number. If you lose 4.0 from 10, it's the same as losing 2.6 from 6.5. If your RJ60+ is performing at the same level as mine you will find that starting at 10 you will end up somewhere around 8, which translates to losing 1.25 from 6.5. If that's the case your RJ60+ is generating at the same level mine is, or about 20g per hour.

It seems like 4 ppm loss in a pool with a CYA of 70 is a massive loss of chlorine, especially for NJ latitudes. You're 5° further north than me. My pool is in 100% sun from 7:30 am to 7:00 pm and I only lose 1.8 - 2.0 FC at CYA 50.

 

[mas985]

It is pretty straight forward. If the RJ30+ is running at 4 amps and produces 1.5 lbs/day, confirmed by @Brett S, the Rj60+ running at 8 amps should produce twice the chlorine.

Here are the calculations plus some measurements I did with the T-15.

Parameter	RJ60+ (sbcpool)	RJ60+	RJ30+	T-15	T-15
Published Production (lbs)	3.1​	3.1​	1.5​	1.45​	1.45​
Production Time (hours)	24​	24​	24​	24​	24​
Nominal Voltage (volts)	22​	22​	21.7​	25​	26.44​
Current (amps)	6.5​	8​	3.8​	7.24​	4.72​
Cells/Group	6​	6​	6​	6​	6​
Cell Groups	2​	2​	2​	2​	2​
Estimated Efficiency	35%​	92%​	92%​	52%​	57%​
1 mole of electrons (Ah)	26.8​	26.8​	26.8​	26.8​	26.8​
CL2 Molar Mass (g/mole)	70.906​	70.906​	70.906​	70.906​	70.906​
Volts per Cell	3.67​	3.67​	3.62​	4.17​	4.41​
Effective Total Cell Current (amps)	39​	48​	22.8​	43.44​	28.32​
Total e- Moles	34.93​	42.99​	20.42​	38.90​	25.36​
Total CL2 Moles	17.46​	21.49​	10.21​	19.45​	12.68​
Total CL2 Production (lbs)	0.96​	3.09​	1.47​	1.58​	1.13​
Percent of Published	31%​	100%​	98%​	109%​	78%​

 

[JamesW]

For what it’s worth, I tried a similar test with my RJ-30+. I ran it at 100% for four hours after the sun had gone down. The FC level in my 14364G pool went up by 2ppm after that run.

In my opinion, this is not sufficient to verify the production. 2 ppm might only be 1 ppm after you account for the test accuracy of each test.

In my opinion, they're not going to get more than twice the efficiency of the Hayward.

Unless someone has lab quality results, I don't believe it.

 

[mguzzy]

I have been following this thread from Day 1.. intriguing. So I am wondering if the issue is not with FC production and instead with FC retention. I see the OP has his CYA at 50. I find I get the best FC retention when my CYA is at 70ppm., right where that more than infamous FC/CYA Levels says it should be. I understand the OP wants to keep the CYA low in case he ha to SLAM, but I wonder if a low CYA might be contributory. I'll shut up now and just watch some more.

 

[sbcpool]

I have been following this thread from Day 1.. intriguing. So I am wondering if the issue is not with FC production and instead with FC retention. I see the OP has his CYA at 50. I find I get the best FC retention when my CYA is at 70ppm., right where that more than infamous FC/CYA Levels says it should be. I understand the OP wants to keep the CYA low in case he ha to SLAM, but I wonder if a low CYA might be contributory. I'll shut up now and just watch some more.

If it was a retention issue I would have a lot of FC in the morning after running the SWG at 100% for 12 hours overnight. Instead I see about 2.5 ppm increase. At it's rated performance I should see FC increase by around 9.5.

 

[Dave_NJ]

When my RJ60+ was running the current indicated on the display ranged between 6.12-6.2 amps. I'm not sure if salinity levels or temperature can influence the current being sent to the cell but mine never went above that range.

I just checked again (the joys of working from home I guess...) and the amperage ranged between 5.6 and 6.25 amps.

 

[mas985]

Both water temperature and salinity affect conductivity. Higher the salt level and/or higher the temperature, the higher the current and the higher the chlorine production. Over small ranges, it is fairly linear.

 

[Dave_NJ]

Both water temperature and salinity affect conductivity. Higher the salt level and/or higher the temperature, the higher the current and the higher the chlorine production. Over small ranges, it is fairly linear.

Interesting. In your opinion given the current range my unit is displaying (5.75-6.25 amps) it would seem the likelihood that it is producing the manufacturer's specified amount of chlorine is not very likely since that would require 8 amps, is that correct?

This is all interesting to me and I appreciate everyone's time in providing all the technical information!

 

[mas985]

It depends on what conditions were used for the specification. Based upon my own testing of the T-15, 1.45 lbs/day is not the maximum nor the minimum but perhaps an average of conditions.

 

[DAB942]

I'm having the same issue. CYA tested at 60 -- added powder.

Tested it three times last week and it was 30. weirdest thing. It has not rained 13000 gallons in the last few weeks -- it has rained several inches. So, I added liquid stabilizer for the quicker injection.

FC is at 1.00, today. I need to look at my pump run time, etc. I have it at 50%. Going to super chlorinate for 24 hrs and test in the morning, and evening. I might not be running it high enough.

 

[Dirk]

Oh me of little help... Here's some items you may or may not find of use...

1. Whenever you fill a pool or spa from empty, you can measure its water capacity by using your house's water meter. They're usually accurate to about 1 or 2%. For next time you empty your spa, or when you replaster. Take a snapshot of your water meter's numbers just before you start the fill, and another immediately after. The difference is your pool's/spa's volume. For best results, minimize water use while the fill is going on: turn off irrigation, no showers, minimal flushes, no laundry or dishes, etc. When you're filling your pool, a little extra-curricular water use won't affect the total all that much, but the less you use, the better the number.

I know you're after flow rate, but knowing water volume can be useful for that. It's certainly useful for when you're calculating dosages. That's why my signature reads 12300, because my pool is 12300 (±1%)!

2. There are services that can RO filter your entire pool and strip it of just about everything, if that is something that would help your situation.

 

[DAB942]

If it was a retention issue I would have a lot of FC in the morning after running the SWG at 100% for 12 hours overnight. Instead I see about 2.5 ppm increase. At it's rated performance I should see FC increase by around 9.5.

After reading your posts, I had my son kick up the SWG and pump run time. Trying to figure out the sweet spot, which I thought I had done. But, I'm seeing the same issues, now, that you are. I made the assumption that 50% would be 50% of total run time, which I run mine 24/7 at varying rates. Now, I'm not sure...

 

[sbcpool]

After reading your posts, I had my son kick up the SWG and pump run time. Trying to figure out the sweet spot, which I thought I had done. But, I'm seeing the same issues, now, that you are. I made the assumption that 50% would be 50% of total run time, which I run mine 24/7 at varying rates. Now, I'm not sure...

The easiest way to test is to run your unit at 100% overnight. If you test FC before start and after finish you'll have a pretty good idea of how much FC the unit is generating. It's not absolutely precise because even a healthy pool will lose a little FC overnight, but it should be pretty close.

If your RJ60+ is performing at its advertised capacity, running for 10 hours overnight at 100% should increase your FC by around 6.3. If your unit performs as mine does you will see FC increase by about 2.0. I'd be interested to see results from a few RJ60+ owners. My suspicion is that the smaller units will perform basically as rated, but that the RJ60+'s advertised performance may be a bit of a marketing gimmick. If that turns out to be the case, and if these are indeed just imported cells from the Chinese manufacturer I linked to earlier in the thread, I don't think Circupool would be totally at fault. The manufacturer I linked to does make cells they claim produce 60 mg/hour, which translates to 3.17 lbs. per day.

FWIW I spoke with Pentair on the phone and the CSR said that the Intellichlor units will actually produce their rated chlorine output. I don't know if it's true as I'd expect any manufacturer's rep to say that, but it's better than the "if the voltage isn't zero it's working fine" that Circupool's reps are using.

 

[JamesW]

Ask for something that shows how they arrived at their figure for output.

 

[sbcpool]

I did, two days ago. No response yet.

 

[JamesW]

Ok, let us know what you find out.

Do you think that it's worthwhile to keep working with the current unit or do you want to send it back and get something else?

 

[sbcpool]

If Circupool genuinely thinks the unit should produce 3 lbs a day and that there's something I can do to get it, I'm certainly willing to try it. If they're going to just tell me that it's working fine and offer no assistance I will request a refund. If they decline that request I still have options to pursue at that point, but I don't want to get ahead of myself.

I am eyeballing a Pentair IC60.

 

[DAB942]

I'm reaching out to them as well. We'll see how they respond.

I can't imagine the company would have the reputation it has if their "stuff" didn't live up to it.

 

[DAB942]

When I asked if I ran it for 24 hours at 100%, would it run for 12 hours, as I heard that it runs a couple hours at a time.

The response: "That is correct, over the 24 hours of run time at 50% output, it would actively generate across that time for a total of 12 hours."

I should have asked if it ran at 50% for 24hrs or cumulatively at 100% for 50% of the time?

The amperage should redcuce if the former is true. I'm not will to watch it

 

[Dave_NJ]

When I asked if I ran it for 24 hours at 100%, would it run for 12 hours, as I heard that it runs a couple hours at a time.

The response: "That is correct, over the 24 hours of run time at 50% output, it would actively generate across that time for a total of 12 hours."

I should have asked if it ran at 50% for 24hrs or cumulatively at 100% for 50% of the time?

The amperage should redcuce if the former is true. I'm not will to watch it

My understanding is the unit has a duty cycle which corresponds to % generated. For example if the duty cycle is 200 minutes, at 50% the cell will turn on for 100 minutes and off for 100 minutes. At 100% the cell will turn on for the full 200 minute duty cycle.

The amperage does not change based on generation percentage.