Can not maintain chlorine with salt cell anymore

[Yarzy]

Hi everyone, I am having an issue with my salt cell keeping up with chlorine production. Just as some backstory, the cell/pool is two years old and I almost never set it higher than 30% in the hottest of months and it was great. Earlier this year I noticed some cloudy water, etc. and finally figured out it that was not detecting flow so I cleaned the sensor, etc. and it seems to have been fine, flow wise, for over a week now. To help combat the lower FC, I upped the SWC to 45%, way over what I normally do but I just wanted to get it back to normal/high levels to make myself feel better. This is also after shocking, etc. Water wise I am good, I put my numbers below but what I am finding is even with the high %, I am not "gain" on the FC but still dropping slowly over time. This time last week I was at 13 FC, now I am at 6, even with the high % set. I took off the cell and checked for build up and it has some, but very minimal I think. A little calcium on a few fins, that is about it. I am currently soaking it in 5% vinegar for the next few hours. The one end of the SWC does smell like chlorine though. I also noticed my salt is somehow hovering around 2900-3000 which I will add more salt today...maybe that is it, I just thought I would run into issues closer to 2800 and below. Any ideas? Is this salt cell dying already? It may still be under warranty (hopefully). Thanks! Numbers below:

FC 6
pH 7.6
TA 80
CH 375
CYA 75
Salt 2900/3000 (within 14/15 drops)

 

[newdude]

Hey Yarz !!!! Sorry it's not going so hot.

First, you Overnight Chlorine Loss Test to prove algae isnt consuming more FC than you make.

Then you do an overnight *gain* test to prove you are/aren't making the expected FC while there's no UV depleting it.


If both tests are good, then we raise you're CYA because you're doing the test wrong. But. I'd rather be an idiot for free, than smart with a big expense (new cell or slam). So if it ends up being the CYA, we all have a hearty laugh and be THRILLED you dodged a spendy bullet.

 

[ajw22]

Do a Overnight Chlorine Loss Test

 

[Yarzy]

I just came back to mention that...my CC are MAYBE 1...I am guessing closer to .5 - .75. Almost clear after one drop, totally clear after a second drop. Not sure if that helps at all.

 

[Yarzy]

Hey Yarz !!!! Sorry it's not going so hot.

First, you Overnight Chlorine Loss Test to prove algae isnt consuming more FC than you make.

Then you do an overnight *gain* test to prove you are/aren't making the expected FC while there's no UV depleting it.

Hey (new)dude! When doing an overnight gain, am I just looking to confirm it goes up or should it go up by a certain amount?

 

[newdude]

When doing an overnight gain, am I just looking to confirm it goes up or should it go up by a certain amount?

We can maths to see what your cell should produce in X hours. Yours produces .27 FC per hour in 23k gallons. 10 hours would be +2.7 FC. (Etc etc etc)

But we need to ensure there is nothing eating the FC before we try or it could be a false fail, you buy a new cell and the new one can't keep up either.

 

[Yarzy]

makes sense. I will run one tonight and report back. Thanks as always!

 

[newdude]

1) OLCT
2) OL*G*T
3) Facepalm and add some CYA. Then do a happy dance it cost $25.

 

[mgtfp]

1) OLCT
2) OL*G*T
3) Facepalm and add some CYA. Then do a happy dance it cost $25.

Interesting typo that led in step 2 to the newly developed Overnight Loss Gain Test.

Just for the books:

1) OCLT
2) OC*G*T

 

[newdude]

Interesting typo that led in step 2

I fouled up #1 too.

 

[Yarzy]

All good, I got you!

 

[wireform]

I'd recommend you do the OCLT without the SWCG on. Make sure of what is or isn't happening. Next night do the gain test to see if the cell is putting out. Make sure you have LC on hand should the OCLT fail and it starts to get too low.

 

[newdude]

+1. Part of the loss test is no addition of chlorine of any kind, in case anyone needs to know that.

 

[Yarzy]

So I just tested it and my OCLT showed a loss of about 1.5, give or take .5 as some points were almost clear. I think I have about 1.5 CC so I guess I need to slam, right? Should I test for gains first, then SLAM? Another question I have is we are due for 4-5 days of rain starting tomorrow. Should I get this shock in ASAP or should I wait until this rain is done as to not mess up the future tests? Thanks!

 

[Yarzy]

One other thing to mention. Today will be mostly cloudy so I dont think there would be a lot of burn off. Also, I did add one more bag of salt to bring that up a bit. With the rain coming and it already being on the low side, I figured that would be okay.

Let me know if you think I should SLAM today or wait until after the rain. Thanks!

 

[MITBeta]

No time like the present to SLAM.

Don’t worry about the OC*G*T until SLAM is complete, and then only if the SWCG isn't keeping up after the SLAM.

 

[Yarzy]

Sounds good, I will get going on it soon. Thanks!

 

[newdude]

So SLAM is always a bummer, but with any luck you caught it in time (YAY frequent testing) and you were keeping the start of a bloom at bay, but consuming the FC the cell made. Hopefully it's an easy SLAM and all will be well soon.

Keep us posted, as always.

 

[Yarzy]

So I wanted to report back with the findings so far and also (shocker!), another question. So, I forgot to shut the cell off last night but we had cloudy, light rain last night (nothing that amounted to much), and it went from a 33 FC down to 25. That tells me either I am fighting something or my cell is shot, hoping the former. It got me thinking though, my water is super clean, my CC is right around .5-1, but I lost a lot last night. I think I saw that FC will get used up fast in the beginning, so how long until I wait to do the OCLT? Do I need to let the FC come down a little before I test that or can I do it night one? I also added another bag of shock just now (I know I should use liquid, but I had this on hand. I tried to dissolve as much as I could in a bucket before adding) which should bring it up around 3.8 based on my simple math, totaling 28/29ish. My CYA is around 70 so I think that is good for round two. I am going to be away the next few days so hopefully bringing it up again will finally kill it all off. The good news is, while I am gone, it is gonna be rainy, cloudy so that should help with the burn off.

Phew, that was a lot. Thanks again!

 

[newdude]

That tells me either I am fighting something or my cell is shot,

With no organics/bathers in the water, you usually lose 0 FC overnight. Maybe there's some residuals from daytime swimming but overall, no overtime loss with sanitary water.

You've all but confirmed algae. Unless you totally botched the tests.

so how long until I wait to do the OCLT?

Usually we wait for clear water but you're already clear. It's up to you how many times you want to wake up early. I'd give it at least a few days of SLAM first. But then again, I'm up early anyway and would likely test for fun.

I am going to be away the next few days

Turn the SWG to 100%. While it won't overcome the algae like you saw to bring you back here this time, it will still add FC daily while you're away and some is better than none.