SWG run time calculations assistance

[Brett S]

I still feel like something is not right with your system. I get that products are often ‘optimistic’ when they list specifications, but in your case getting 1/3 of the published output seems to be well beyond that.

I’ll test this with my RJ-30+ tonight and see what I come up with. I’m going to wait until this evening though because I know that if I did it during the day the direct sunlight would affect the results.

According to poolmath, running my RJ-30+ at 100% for four hours should produce 2.1ppm of chlorine in my 14364 gallon pool.

I’ll let you know how it goes.

On a side note, did you double check the cell type listed in your RJ-60+ to make sure that it is listed correctly? And even check the sticker on the cell itself to make sure that you really do have an RJ-60+ cell.

 

[sbcpool]

On a side note, did you double check the cell type listed in your RJ-60+ to make sure that it is listed correctly? And even check the sticker on the cell itself to make sure that you really do have an RJ-60+ cell.

Yes, sir.




Just in case something's awry electrically, if someone could check their RJ60+ cell voltage and amperage it would be helpful. Once stable mine is around 20V 6.5A.

EDIT - Looks like the cell is working as designed.

https://www.circupool.com/assets/doc/CircuPool-RJ-Troubleshooting-Guide.pdf

Cell Voltage
Range can be 20.0-26.0 volts (while generating). If the voltage reads near 10.0-13.0, the system is configured to accept 220V but is only receiving110V.

Cell Current
Range can be 2.50-8.00 amps (while generating). May be 0 during normal operation when system turned to less than 100% output and is in its rest mode. If present, a hyphen (-) indicates polarity, and not a negative value.

 

[JoyfulNoise]

Can you please post the Amps and Volts when the cell is generating chlorine and number of plates you see inside the cell (my guess would be 9 or 13 but I'd like an exact count). Also, and this may not be entirely possible given the configuration, you should see bubbles forming on the plates; does the gas generation inside the cell look uniform (ie, bubbles being generated evenly across all plates)?

 

[sbcpool]

From all appearances, the bubbles seem to come from inside. I don't see anything forming on the metal "shell." I can see that the water is "foggy" (with random fluctuations and eddies like smoke) after passing the plates and the returns have a lot of bubbles.

I'm wondering if it's possible that the test strips and the control unit are being "fooled" into thinking the salinity is higher than actual. It's just speculation, but if the chloride levels were low but some other ion concentration was really high wouldn't that make it slower to produce chlorine even though the conductivity seemed right? Does anyone know if the test strips are actually measuring chloride?

 

[JoyfulNoise]

I won't belabor this thread with a lot of math, but 6.45A on a bipolar cell design with 13 plates will yield, on average, ~3 lbs of chlorine gas per 24 hours. So I believe the cell is operating correctly.

As for testing salinity, you should really be using the Taylor K-1766 test kit and not strips. Relying on strips and/or the salinity readout from the unit is generally not a good idea as those are only proxy methods of determining salinity; strips are especially bad. The K-1766 is a titration test that measures chlorine ion (Cl-) directly and gives you the salinity in ppm NaCl. So it is a much more accurate test. That said, your salinity is probably not that far off from what the unit needs to generate chlorine and the chlorine output is fairly immune to the concentration as long as you are within recommended levels. What will typically happen if the salinity is too high or too low is that you will "stress out" the power supply and possibly damage the plates. This is why most units will shutoff when the conductivity doesn't appear right.

Also, does this control unit measure temperature in some way? Some of the SWG's actually have internal programming that dials back the output based on water temperature to try to optimize chlorine output and to also sense when the pool water temperature is too low for generating chlorine. Make sure whatever temperature probe it is using is accurate and functioning.

 

[JoyfulNoise]

Forgot to ask - how much plumbing run is between the cell and the pool returns?

 

[Brett S]

I won't belabor this thread with a lot of math, but 6.45A on a bipolar cell design with 13 plates will yield, on average, ~3 lbs of chlorine gas per 24 hours. So I believe the cell is operating correctly.

Circupool claims that the RJ-60+ will generate 3.1 lbs of chlorine gas per 24 hours, so that’s certainly in line with your math. But I’m not sure that I agree with you that the cell is operating correctly. He stated that when he runs the cell at 100% for 4 hours he only sees the chlorine level rise by 1ppm in his 20,000 gallon pool. If the cell was really producing 3.1lbs of chlorine gas per 24 hours then he should see the chlorine level increase by 4.3ppm over a 4 hour run at 100%, no? Or are we missing something here?

 

[sbcpool]

Also, does this control unit measure temperature in some way? Some of the SWG's actually have internal programming that dials back the output based on water temperature to try to optimize chlorine output and to also sense when the pool water temperature is too low for generating chlorine. Make sure whatever temperature probe it is using is accurate and functioning.

Yes, it measures temperature and seems to be in general agreement with a spirit thermometer in the pool. The pool temperature is currently around 83°F.

Forgot to ask - how much plumbing run is between the cell and the pool returns?

There are four returns. The closest return is in the spa about 15 feet from the pad and the furthest is in the deep end, about 50 feet away.

 

[Brett S]

I’ll test this with my RJ-30+ tonight and see what I come up with. I’m going to wait until this evening though because I know that if I did it during the day the direct sunlight would affect the results.

According to poolmath, running my RJ-30+ at 100% for four hours should produce 2.1ppm of chlorine in my 14364 gallon pool.

I’ll let you know how it goes.

Well, I went ahead and did the test and in my case the numbers were pretty much exactly what would be expected. I ran my RJ-30+ at 100% for four hours in my 14364 gallon pool and my FC went up by 2ppm.

I still have no idea what it is, but it really seems like something is wrong with your SWG.

 

[sbcpool]

I wish I could find a Taylor kit locally, but nobody has it. I guess I'll order it and wait a week. :/ I don't think low chloride is the issue, though, since I ended up adding 480 lbs of salt myself. Even if there was 0 chloride present when I added it (unlikely given years of chlorine additions and no draining), my addition alone would have added 2,900 ppm.

 

[JoyfulNoise]

Can you close off the spa return and perhaps cap/plug the next nearest return? Can you run the pool with just the two returns? It would be nice to see the SWG run for at least 8 hours of output overnight and then measure the change in FC.

 

[sbcpool]

I can't close the returns as they are just open ends of 3/4-inch pipe. No threads, no eyeballs, just holes in the pool wall. The way the plaster is I don't think I could get a slip plug in there. The spa and the pool are the same water level with a spillway between them, so what goes in there comes out in the pool anyway. There's no suction from the spa during normal operation of the pool.

I will run the pump for 8 hours and report FC before the sun hits the pool. My FC was 5.6 this evening after sunset. In theory it should be in the neighborhood of 11.7 in the morning, but I suspect I'll find closer to 7.2.

 

[sbcpool]

Pump ran from 22:13 to 06:06 (Intermatic timer isn't precise). Final FC 7.4.

Pool Math's calculated FC based on 8 hours runtime: 11.8

 

[mknauss]

@circupool
A notice if they visit the forum.

 

[sbcpool]

I think I'll try cleaning the cell today. I don't really suspect the cell is fouled given that the voltage is on the lower end of the normal range, suggesting that there's no a lot of resistance. But I'm just trying to eliminate all the variables I can at this point.

Since I'm new to the SWG world, I don't know what it looks like when a cell gets old and dies. Is what I'm seeing what you would expect, or are there other tell-tale signs, like high resistance, etc.?

 

[JoyfulNoise]

That’s highly unusual. You really should have eyeballs on the returns to help control the flow and directions of the water. Without eyeballs, it’s highly likely the majority of the return water is flowing out if the nearest return with substantially less water coming out of the farthest returns. You can buy some rubber expansion plugs that are used by people who close their pools during winter.

One more question, you mentioned bubbles - do all of the bubbles exit the spa return or are they coming out of the returns evenly? Is it a small amount bubbles that are easy to see separately or is it a huge amount of bubbling and/or cloud of micro-bubbles like when you shake up a glass of soda?

 

[sbcpool]

That’s highly unusual. You really should have eyeballs on the returns to help control the flow and directions of the water. Without eyeballs, it’s highly likely the majority of the return water is flowing out if the nearest return with substantially less water coming out of the farthest returns. You can buy some rubber expansion plugs that are used by people who close their pools during winter.

This is what the returns look like, all 8 (5 in the spa and 3 in the pool).

I can't plug the spa return. If I plug the spa the water will sit stagnant, not receiving any circulation or chlorine.

One more question, you mentioned bubbles - do all of the bubbles exit the spa return or are they coming out of the returns evenly? Is it a small amount bubbles that are easy to see separately or is it a huge amount of bubbling and/or cloud of micro-bubbles like when you shake up a glass of soda?

If I had to assign a percentage I would say about 10% of the bubbles come out of the spa return, maybe 5% each come out of the mid returns, and the other 80% comes from the furthest return. I think a video and some pictures are in order.

Click here for video of bubbles coming from furthest return.

The bubbles are enough that the coping gets wet above each return.

 

[sbcpool]

Are the last few numbers of the cell's serial number a date of manufacture? If they are, mine is a very old cell.

EDIT - I think it's just a 64-bit hexadecimal value, but asking just in case. Trying to investigate every possibility.

 

[HeyEng]

I think I'll try cleaning the cell today. I don't really suspect the cell is fouled given that the voltage is on the lower end of the normal range, suggesting that there's no a lot of resistance. But I'm just trying to eliminate all the variables I can at this point.

Since I'm new to the SWG world, I don't know what it looks like when a cell gets old and dies. Is what I'm seeing what you would expect, or are there other tell-tale signs, like high resistance, etc.?

It does sound like you have an issue with it. Your description of the fog/bubbles/etc. and your voltage/amps is EXACTLY what I am seeing with my RJ60+. I am running it at 60% for 6 hours a day (split into two cycles... 9p-midnight and 9a-noon) and it's holding right at 7 PPM (which is a little high for my CYA of 70). I was running it at 75%, but it had pushed it up to 9 PPM which was too high for me. I don't know *exactly* how much FC I am using in a day, but on the hottest days, it is close to 5 or 6 PPM per day.

Did you buy it directly from Circupool or a reseller? I would inquire as to getting a replacement unit. I think that would probably be the easiest fix for it.

 

[Brett S]

Are the last few numbers of the cell's serial number a date of manufacture? If they are, mine is a very old cell.
EDIT - I think it's just a 64-bit hexadecimal value, but asking just in case. Trying to investigate every possibility.

I doubt it’s a date, but if so, mine is a similar age.