Hayward GLX-LOCAL-PS-8 SWG and T15 not producing chlorine.

[coletjd]

So last year my "check system" light came on and I found out the relay solder pad had heated and melted. There were many threads to this and how to repair. I fixed this and the system ran fine at the end of last season and fine when I opened this year. About 1 month ago I noticed my chlorine dropped off when I had it set to about 50%. No system lights or any other indicators something is wrong. I shocked/ balanced CYA and increased the chlorinator 80% and a week later the chlorine dropped off again. I have done this mutliple times and superchlorinated looking some sort of life and nothing. Water is fine right now because I have been persistent with my BBB. This afternoon I took my cell to a shop to get tested and they said it was fine.

Voltage and current reading in pic.
V = 25.93
A = 6.61
Cell temp is 80F
3200 PPM which matches my salt test strip

My cell is the T15.


Any ideas, measurements, tests, suggestions...........

My next thread will probably be asking the group for what I should replace the AQL PS8 with.

Thanks in advance, Joe

 

[JamesW]

The numbers look good. Based on the information you have provided, the system seems to be working correctly.

What are the timers set to?

What is your cya and your lowest fc level in the last two weeks?

I would recommend getting a fas dpd test kit and the Taylor k-1766.

 

[coletjd]

Ok, so if those readings are correct then there is 99.9% accuracy that it is not a hardware problem probably more chemistry related.....

Timers are set to run at 12:00PM to 8:30PM.

My CYA is at 80 ppm. The lowest it has been would be maybe 50.

As of earlier today
FC - 2
CC - 2
Alk - 90
PH - 7.4
TH - 300
CYA - 80

 

[JamesW]

I would go to an fc of about 20 and do an overnight chlorine loss test. If you lose more than 1 ppm or if the water is not clear or if there is any algae, you should do the SLAM process. Once the SLAM process is complete, maintain fc at 15% of cya for a week and then at 7.5% of cya thereafter.

Based on your run time of 8.5 hours, you might have to increase the percentage of the chlorinator.

 

[coletjd]

Thanks, very helpful. I will try the OCLT tonight. I use a solar cover, (the cheap blue 6mm one) should I leave this off for the test or leave it on like I normally would?

I guess the other thing I can do to determine if the cell is working or not is to superchlorinate for 6 hours during the night to see if the FC increases.

 

[ping]

This is most likely a chemistry issue and the pool has nascent algae in it. Without a FAS/DPD test for FC you can not properly do an OCLT to determine the FC loss overnight. You will also need this test to complete the SLAM process.

The multiple shocks are not killing all the algae and when the FC drops to normal levels the algae starts to multiply and the SWG falls behind again. You can keep on trying to shock the pool and hope it kills the algae or you can follow the SLAM process and for sure kill all the algae.

 

[coletjd]

The SLAM process is now in full swing as I added 288oz of 10% last night taking my FC up to 20ppm as James suggested. Immediately my CC increased with my FC. This morning when I checked both levels remained high. I left the solar cover off, turned the heater and cell off while I complete this process. How long do you estimate I can do this.

I agree this must be algae, the unusual thing is the water is crystal clear everything else is stable. Hindsight we have had a cooler summer this year than previous years and I have used my solar cover more this year than any others as my family prefers the water warmer (>85F) than my personal liking ~80F. After reading the thread below I think there be some interactions with my cover use and water treatment or I should say lack of treatment. Thanks to your advice I am confident this will be resolved in a few days.

 

[ping]

Each SLAM is different and there is no telling on how long it will last. To insure that it goes as fast as possible, remove and scrub any lights, make sure you brush the pool, and keep the FC level at or slightly above SLAM levels at all times. I've seen SWG pools that look clear take from one to seven days to pass the three criteria of the SLAM process.

 

[coletjd]

My K-1515 finally came today.

Here is how it went..........please confirm I did this correctly.
I had 17 drops of 871 reagent using the 10mL reference so I had 8.5ppm FC. I figure I have estimated chlorine loss of ~4ppm per day with solar cover on which seems right with a CYA at 50-60.

Next added 5 drops of the titrating 003 and it did turn light pink.

Added only 2 drops of for it to be completely clear again. Based on this I almost meet the successful SLAM requirements of CC 0.5 and below. Rain in the forecast all weekend so I might have to wait to do the OCLT next week.

 

[ping]

Your testing is fine. Since it took two drops of 003 the CC is 1 which means you need to run the SLAM Process.

The pool is losing a larger amount of FC in a day that I would think it would with a cover on it. I would start the SLAM Process now even though rain is in the forecast, see my signature for the SLAM Process.

 

[Hayward Pool]

How old is the T-15 cell? They last 3-5 years.

 

[coletjd]

How old is the T-15 cell? They last 3-5 years.

3-5 years assuming 12 month year? My assumption is that it was installed new with the pool in Summer of 2009 so it would be 6 years old. When I get home I will look for date code to confirm. Keep in mind I know that this pool had very minimal use from 2009 to 2011 when I bought the home and even in the last four years it is only opened from mid May to Mid September.

 

[coletjd]

In conclusion I have met all the success criteria for SLAM. The last three times I have checked there is less than 0.5CC. I would prefer that it was zero but it always turns just a little bit pink after the 5th drop and is always eliminated again with only one drop of the 871.

I still have my cell turned off as my FC level is at 12ppm and my CYA is at 40. Next I suppose I should allow my FC level to come down to normal level and then turn my cell back on at ~60%. If I do this and my FC level drops off to zero again I will be completely stumped. If anyone else knows of a good independent check or test that I can do on the cell please let me know.

 

[chem geek]

If you know your flow rate you can test the water coming out of the returns to see if the FC is elevated by the amount you expect. The T15 is supposed to output 1.45 pounds of chlorine over 24 hours. That is 457 milligrams per minute. So if your flow rate were 60 gallons (227 liters) per minute, then that you should expect a 457/227 = 1.8 ppm FC increase out of the returns above the FC level of the bulk pool water.

 

[ping]

You can also loosen the cell union and take the water sample right at the cell and run the comparison to the bulk pool water.

 

[coletjd]

You can also loosen the cell union and take the water sample right at the cell and run the comparison to the bulk pool water.

If you know your flow rate you can test the water coming out of the returns to see if the FC is elevated by the amount you expect. The T15 is supposed to output 1.45 pounds of chlorine over 24 hours. That is 457 milligrams per minute. So if your flow rate were 60 gallons (227 liters) per minute, then that you should expect a 457/227 = 1.8 ppm FC increase out of the returns above the FC level of the bulk pool water.

Taking a measurement right out of the cell would be difficult based on how the plumbing was done and location of the cell. Also knowing the exact flow rate seems trivial as well since I would have to know the exact routing and length of my return lines (4 of them) and add in the flow resistance. My guess is with 4 lines averaging out to about 35 feet which would give me <50GPM.

All the guessing aside did a OCGT in which I turned the Chlorinator on at 100% for exactly 10 hours and my FC went from 3.5ppm to 8.5ppm with zero CC present.

To summarize the T15 swg system that has been running for 4yearss effectively at 55% but now appeared defective because of some sort of nascent algae bloom that appeared although it was not noticeable at all to the naked eye and did not impact anything else. This may have been in parallel with the Tcell aging and losing efficiency but 2ppm of FC being added was not enough to overcome. Moving forward I have adjusted my time from 12noon to 8PM and increased to 80% doubling my normal daily increments. I will try this for a couple of weeks and see how it does. If it is too high then I will adjusts this level down 5% until stabil. If it drops to zero again then what? Remember that for a month I was going in and shocking using liquid bleach which temporarily raised and maintained those levels but it never stayed.

Follow/up questions.........where did this invisible bloom come from and how to prevent it? My theory above is that algae is living on top of the solar cover and pollutes every time it is moved or opened. It is the cheap cover that only made it about 1.5years and is already shredded and cracking allowing water to rest within the bubbles.

 

[ping]

It is time to get rid of the cover. The algae might be getting introduced every time the cover is put on the pool. Any time the FC is below the minimum amount per the FC/CYA chart the pool is suspect to algae growth.

Read up on the OCLT as it doesn't look like you have properly run the test to determine if there is algae in the pool.

 

[coletjd]

It is time to get rid of the cover. The algae might be getting introduced every time the cover is put on the pool. Any time the FC is below the minimum amount per the FC/CYA chart the pool is suspect to algae growth.

Read up on the OCLT as it doesn't look like you have properly run the test to determine if there is algae in the pool.

Agreed on ditching the cover. I was going to try to finish out the season but that thing went downhill very fast.

Why do you think that it was not tested correctly? The first couple of times it was run I was seeing higher levels of CC and no FC which makes sense because the cover was on during longer durations. After the SLAM was completed I am now seeing no CC. During the SLAM process I was more active with the cover and probably killed the algae on the cover. My concern is that the algae will come back if my FC levels are only going to maintain a consistent 4-5ppm FC.

 

[ping]

When I read this sentence in the above post, "All the guessing aside did a OCGT in which I turned the Chlorinator on at 100% for exactly 10 hours and my FC went from 3.5ppm to 8.5ppm with zero CC present.", I thought you left the pump running with the SWG on and did the OCLT.

Anyways, it looks like the SWG is working fine and I would see how things go without the cover for a week.