Squeeze last bit of life out of cell?

[Saturn94]

Your average yearly chlorine cost just keeps shrinking and shrinking.

Yep. I figured it out recently. I’m at about $135 a season (May-Oct) including upfront cost of SWCG (installed early 2004), repairs (new main board in 2009), and replacement cell costs.

 

[Saturn94]

I think that you have a pretty good plan.

Uh oh, may have jinxed myself. FC has dropped past couple days despite % setting being higher than usual. Time to do an OCLT to rule out something in the water (not likely, but gotta rule it out).

 

[Saturn94]

@JamesW

The OCLT passed easily with no FC loss. So it appears the cell output is reduced. The cell readings are normal and instant salt level readings between polarities are the same (3400 on T9 setting; actual salt level per Taylor drop test is 3000).

Should I just keep increasing the % on time until it just can’t keep up any longer? This morning I increased it to 80% @ 10hrs. Normally, with a healthy cell, it would be at 50%-60% @ 10hrs. Or is it time to retire this cell?

Thanks.

 

[mas985]

My experience has been that once the cell starts to degrade, it goes downhill pretty fast so this method may not end up extending the life of the cell all that much.

 

[JamesW]

(3400 on T9 setting; actual salt level per Taylor drop test is 3000).

The cell is producing about 75% of the expected output of a T-15 or about the expected output of a T-9.

The T-9 puts out about 1 lb of chlorine gas per day.

16 oz of chlorine gas added to 20,000 gallons of water will provide 6 ppm of chlorine.

80% for 10 hours is only going to provide 2 ppm.

I would go to 100% for 12 hours to provide 3 ppm per day.

 

[Saturn94]

The cell is producing about 75% of the expected output of a T-15 or about the expected output of a T-9.

The T-9 puts out about 1 lb of chlorine gas per day.

16 oz of chlorine gas added to 20,000 gallons of water will provide 6 ppm of chlorine.

80% for 10 hours is only going to provide 2 ppm.

I would go to 100% for 12 hours to provide 3 ppm per day.

So a T15 cell with the controller set to T9 will output less chlorine than with the controller set to T15?

Last August when I first changed the controller setting to T9 for the “newer” T15 cell I was using, I didn’t have to adjust %/pump time up to compensate. I guess I assumed a T15 cell would output the same on either the T15 or T9 setting as long as volts and amps was in normal range. What am I missing here?

Right now the daily FC loss is running about 1.5-2ppm a day. So to calculate % and pump runtime using the Pool Math app, should I be selecting the T9 cell since that’s where the controller is set?

Thank you again. This is very educational.

EDIT: Rereading your post, I think may be misunderstanding. Are you saying because the T15 is outputting about the level of a T9 (calculated based on the actual vs displayed salt readings?), that’s why the T9 output level should be used to calculate % and runtime?

 

[JamesW]

So a T15 cell with the controller set to T9 will output less chlorine than with the controller set to T15?

The setting has no effect on the output.

Your old cell is underperforming because it is old and mostly worn out.

The setting only keeps the salinity reading high enough so that the box does not shut down due to low salinity.

 

[Saturn94]

My experience has been that once the cell starts to degrade, it goes downhill pretty fast so this method may not end up extending the life of the cell all that much.

This trick did get me through the rest of the season last year (late August through the end of October).

 

[Saturn94]

The setting has no effect on the output.

Your old cell is underperforming because it is old and mostly worn out.

The setting only keeps the salinity reading high enough so that the box does not shut down due to low salinity.

Ah, thanks for the clarity.

After rereading your post, I thought I might be misunderstanding (I was).

 

[C0d3Sp4c3]

My OEM T-15 barely made it past it's 4th year. Jan this year I hacked the r1.59 board to read 65°F fixed and set the controller cell type to T-9. Today, I am down to T-5 on the settings. Again this is just me!

 

[Saturn94]

My OEM T-15 barely made it past it's 4th year. Jan this year I hacked the r1.59 board to read 65°F fixed and set the controller cell type to T-9. Today, I am down to T-5 on the settings. Again this is just me!

The “oldest cell” I’m currently using lasted 7 full seasons before I replaced it. The “newer cell” I have has 6 full seasons on it. So I can’t complain too much about their lifespan.

The original cell that came with the unit only lasted 4 seasons, but was subjected to pool store advice abuse.

 

[Saturn94]

The setting has no effect on the output.

Your old cell is underperforming because it is old and mostly worn out.

The setting only keeps the salinity reading high enough so that the box does not shut down due to low salinity.

I think it’s time to give up on the oldest cell (bought 2008). Even at 100% (10hrs) it can’t keep up now. I could try increasing pump time (single speed pump), but I’d rather not, and don’t think I’d be able to squeeze much more from this cell anyway.

This evening I installed the T15 cell from 2015 (left controller on T9 setting). We’ll see how well it does. It was working well on the T9 setting when I closed last fall.

Next month I think I’ll break down and buy a new cell. I do have some questions about compatibility of the different Hayward “T15” model variations (Hayward T15, Swimpure T15, etc; though not interested in generic cells) with my Goldline Aqua Rite controller, firmware v1.50. Should I create a new thread for this?

 

[chlorinatorpro]

You could always try the T-5 setting, then the T-3 setting assuming you would want to run the pump more than 10 hours per day. Then you would have to factor in the extra $ of energy your spending to see if it makes sense.

 

[Saturn94]

You could always try the T-5 setting, then the T-3 setting assuming you would want to run the pump more than 10 hours per day. Then you would have to factor in the extra $ of energy your spending to see if it makes sense.

Thank you for the suggestion.

My understanding is that changing the T cell setting just tricks the controller into thinking the salt level is ok. My T15 cell from 2008 is still reading salt level ok on the T9 setting, but it’s not producing enough chlorine anymore. So I‘m thinking it’s just worn out and changing the controller setting to T5 or T3 won’t make a difference in this case (I’m not particularly interested in increasing pump time). Am I understanding this correctly? With over 7 seasons of use on it, it’s probably just time to let this cell go.

In the past I would have just bought a new cell and moved on instead of trying to get every bit of chlorine production out of the cell. But at today’s prices, I appreciate these tricks to squeeze out as much as possible from the cell. The T15 cell I bought in 2015 was $398. Now I’m seeing it at $650 - $700.

 

[chlorinatorpro]

So again, how much extra life did you get by changing the setting to T-9? I understand results may vary from user to user.

 

[Saturn94]

So again, how much extra life did you get by changing the setting to T-9? I understand results may vary from user to user.

The cell from 2008 with 7 full seasons of use on it has lasted just under a month on the T9 setting.

The cell from 2015 ran fine for a little over 2 months on the T9 setting last season (2020 was season #6 on this cell). It was still running fine on the T9 setting when I closed last fall. I reinstalled this cell yesterday evening. We’ll see how much longer it lasts on the T9 setting.

At a minimum, this has been educational.

 

[Saturn94]

Update:

I went ahead and ordered a new cell (ouch! The price has gone WAY up since 2015! ). Even though the current T15 cell (purchased early 2015) is still keeping up on the T9 setting, it’s obvious performance is reduced and approaching end of life. I’d hate for it to die while I’m on vacation and come home to a mess. I’ll just keep it as a backup.

I appreciate everyone’s advice and feedback.

 

[Saturn94]

@JamesW

Ugh! The new T15 cell (model TCell15SWP, suppose to be compatible with Aqua Rite controller) arrived today and I installed it, changed the controller setting to T15, and fired it up. For some reason with the new cell I‘m still getting a low instant salt reading! In fact, it’s the same instant salt reading the old cell (from 2015) gives on the T15 setting!

Now I‘m wondering if the problem all along wasn’t the cell, but something else.

Here’s the diagnostic readings for the new cell, controller set to T15

2200 (I reset the Avg salt setting to match the instant setting)
26.2v
5.06a
80P
-2200
AL-0
r1.50
t-15

I turned it off and back on to switch polarities, the only difference was 25.7v, 4.96a. Everything else was the same.

Of course, shortly after it powers up, the Low Salt and Check Cell lights come on (steady) and it stops generating (Generating light shuts off).

Any idea what may be going on here? Anything I can check?

Thank you.

PS - I just check salt level with the Taylor drop test; 3000ppm (tested twice to confirm)

Edit: I also made sure the salt cell plug contacts were clean. They looked brand new on the controller, but I cleaned them anyway. That made no difference. Also, if it matters, the controller was installed March 2004 and the main board was replaced in spring 2009.

 

[JamesW]

Check the salinity two new different reliable ways.

 

[Saturn94]

Check the salinity two new different reliable ways.

My apologies, I don’t understand. I checked the salt level twice using the Taylor drop test kit K-1766 (reagents aren’t expired, stored in dark/tackle box inside house). I don’t know what other test is reliable.