Tcell15's end of life indicator?

[amati5]

Hi, does the board (Aquarite, pre 2008) show any kind of indication or just produce less and less?

My past units since 2004 never showed any signs after conistently 3 1/2 years and i had always found out the hard way by doing all kind of checking before getting a new one. This current one has only been a little 2 yrs and is doing the same. Last night i superchlorinated it and this morning, after 10hrs, it only raised fc from about .5-1 range to 1-2 range. Last week i took the cell for testing at the store and it passed. It seemd they only test to see if it work electronically, not if it produce decent amount of fc. The rep from Hayward also said if all indicator lights show normal it means the cell works. Can the computer tell if the cell is working?

Also, my pool has been high salt up to 4000 in the past year (didnt want to drain due to the drought), would that affect the cell's life.

The rep from Hayward also asked me to check for phosphate and nitrate. Pool store couln't do nitrate and my phosphate was zero (i doudt if the guy knew what he was doing). Do these chemical affect the cell's life? I was told phosphate is not important and stopped using them.

Thx

 

[abycat]

my 29000 gal pool has 3 of those cells and 3 controllers. One is on 5% and the other is connected to the chemtrol 250 controller on the orp side. I set the controller to 25% so it doesn't over chlorinate. The third controller is unnecessary but is installed none the less. With the max 27 patron bather load the two cells keep up just fine with fc around 2.3 going up to around 2.7 when the second kicks off. I havnt seen yet but im guessing I don't dip under 2. I do get 75 gpm with a 24/7 pump run time. technically your pool is to big for your cell but I can make javex with 3! What type of test kit you using?

- - - Updated - - -

ooops the t15 is rated for 40000 gal. I was thinking it was 15000. You have to have a cell issue or testing is not accurate.

 

[ping]

What you need to do is an OCLT to determine if there is nascent algae that is consuming the FC. What test kit do you have?

Turn the dial to 100% and post the diagnostic readings.

 

[amati5]

I tested with TF test kit and have no combined chlorine. My pool has no sign of algae.

Back to the questions,

1 Does the board show any indicator at the end of the cell's life?

2. Does running with high salt (3900) reduce cell's life

3. Does phosphate affect fc level?

I just found out that some algaecide remove quite a bit of fc which might be the case with my pool. I did notice my fc and ph droped to almost zero after adding. I am not sure why it does that.

 

[mas985]

OCLT is not about CC, it is about chlorine loss overnight.

1. No
2. No
3. No - But algae growing does so run an OCLT. You can't always tell if algae is just starting.

But an old SWG cell will reduce chlorine output. You can have it tested at a pool store.

 

[chiefwej]

An aging cell will also show salt readings that are lower than actual. So if you see that salt readings on the control panel showing low salt and testing shows that actual levels are much higher, the cell may be failing.

 

[amati5]

Salt ave reading is actually higher than instant reading (matched pool store's), about 100 higher.

I am not sure if the test at the pool store can tell a failing cell. All he did was pouring their salt water to the cell and watch if it fail or pass electronically. There was no output liquid to test for fc unless the process was within the system. Looked like they just test to see if the board function.

I also tested the overnight fc lost when this problem started

Thx

 

[mas985]

Salt ave reading is actually higher than instant reading (matched pool store's), about 100 higher.

Fairly common. The ave salt is determined from the start of the cycle when the current in the cell is higher because the electronics have not warmed up yet due to the high current.

I am not sure if the test at the pool store can tell a failing cell.

Others on the forum have had success when testing cells in a auto tester. They use a specific salt level and temperature so the current should be within a specific range. If it is too low, it is likely the cell is bad. There is no need to test the output FC level because current is proportional to FC production. But you did not say if the cell passed or failed.

 

[amati5]

It passed . So does that mean if the plates in the cell worn out, the computer wouldn't see normal operating current and would fail the cell? I guess it makes sense since current value is pretty much determined by the load and in this case the plates are the load.

 

[mas985]

So does that mean if the plates in the cell worn out, the computer wouldn't see normal operating current and would fail the cell?

Yes

BTW, what is the CYA level?

 

[amati5]

60 now because i drained some water to lower salt. The problem started even when it was at 80. I think my problem is the swg not making chlorine enough, not losing. I superchlorinated over night to test and it only made enough to raise 1 point at next early morning.

 

[mas985]

I superchlorinated over night to test and it only made enough to raise 1 point at next early morning.

Did you measure that with a FAS DPD test kit using the 25 ml mark?

8 Hours of 100% chlorine production should raise FC by about 1.7 ppm and close to the FAS DPD resolution depending on sample size. If you used OTO, then it could easily be that much.

 

[amati5]

In the past weeks, i just use the basic kit.

 

[mas985]

Then how do you know it was only a 1 ppm rise? Those kits have very poor resolution and you really can't tell if it is 1 ppm rise or 2 ppm rise. You really need to get a good test kit with FAS DPD if you really want to know what your SWG is doing. More than likely, your SWG is operating and producing what it should be.

 

[amati5]

I superchlorinated much more than 8 hr, at least 14 hrs.

 

[ping]

If all is well with the SWG then it added about 3ppm of FC in that time, but the pool also consumed some of it during normal operations.

Without doing an OCLT you will never be able to rule out organics as the cause of your problems.

Since the cell is clean, it passes at the store, the salt level is accurate on the readout, and the pool has low chlorine levels, I would say the cell is most likely fine and organics is the cause of your pools problems. This is a very common problem with SWG pools and that is why manufactures say they want zero phosphates. It's kind of their way to rule out algae because they can't do an OCLT.

 

[mas985]

I superchlorinated much more than 8 hr, at least 14 hrs.

Then some of that time had to have been during the day where UV extinction comes into play. If you really want to know what your SWG is producing, you first need to get a decent test kit (FAS DPD) that can accurately measure the FC to 0.2 ppm resolution. Then I would run a set amount of time, non daylight hours, with just the spa, since it is a lower volume and you will get a higher FC rise in a smaller amount of time, and then calculate the production.

 

[amati5]

Again, the advice from here is spot on. I started the process again to check for oclt and shock the pool and my pool is now working again. I hestitated to do the process again because i had already done it when the problem started at the beginning of the summer. I think what happened was right after everything was in order, i hooked up the water hose for the slide which has been sitting with water inside and probably full of algae. And it consumed the fc overnight. I only connected it to the slide during the summer and this explains why i kept getting the same problem every year.

Thx again forvthe advice.