Cannot maintain chlorine levels

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
I have a new pool, 4 months old. Hayward T15 swg. I cannot keep the FC levels up despite running the cell at 95% for 12 hours a day for the past month straight.

CYA is 55. Ph has been at 7.4 for months and I have added zero acid. TA is 80. Salt is 2900. I have suspected that I have a bad salt cell since I can’t get the levels up and my ph doesn’t rise (I am told swg systems raise it). If I add some Chloroboost or liquid chlorine it will raise but fall back down after a day or so.

I contacted my builder about it and he says he can’t see anything wrong with it and thus checked for nitrates. He says they are 7ppb and claims this is why I can’t keep FC levels up.

I have done a lot of googling and get mixed results about whether nitrates affect FC and what levels are bad if so.

The pool is cloudy now and there are hints of algae starting. Anyone have an opinion on the nitrates? I’m still not convinced my swg is working up to par.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
23,036
Laughlin, NV
Welcome to the forum!
You do not tell us the volume of your pool. Can you fill out your signature?
Most likely the SWCG cannot keep up with the loss of chlorine due to the algae in your pool. Nitrates are not material to pool water chemistry.
You need to follow the SLAM Process. To do that, you need a proper test kit, see Test Kits Compared. I suggest the TF100. A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

While you are waiting on your test kit, add 5 ppm FC worth of liquid chlorine / plain bleach to your pool each evening with the pump running. This will replenish the FC lost each day to the sun and also inhibit any algae in the water from growing further.
I suggest you read ABC's of Pool Water Chemistry.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
15,391
Bedford, TX
DD,

I doubt anything is wrong with your cell.. I suspect the main problem is you were running your FC way too low and you allowed your pool to get an algae bloom, even if you could not initially see it.

No salt cells can make more chlorine than the algae can consume...

I suggest that you read this... ABCs of Pool Water Chemistry

To fix your pool, you will need to do what we call a SLAM... SLAM Process

Thanks,

Jim R.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
12,045
Evans, Georgia
I also prefer the TF100 test kit. Sure it's $70, but it will save you that and more because with that test kit you learn and will only add to the pool that which it *needs* and will get the response you expect. www.tftestkits.net

One way to test if your cell is working is to have it running at 100% so that you see the poof of white smoke (gas) in the cell- it should if its producing. Then grab a cup and slide it upside down in to the water directly in front of the return. Turn it so you quickly fill it only with fresh returned water and test that for FC. It should test higher than the rest of the pool's FC.

Maddie :flower:
 

Jason245

Well-known member
Jul 27, 2019
72
Fort Lauderdale FL
you didn't say what your FC levels were (or if they were at Zero), but after you are done slamming you might want to adjust your CYA up to the recommended levels.

I am in a similar situation to you and have passed the SLAM tests so the best answer I have is the darn UV rays during these hot months and my SWG being undersized for the job.

If you pass the SLAM, and CYA is ok... the only answers I have found (and someone can chime in ) is run the SWG longer (I am actually debating running 24/7 until the UV gets better later in the year) or supplement with chlorine (which I am doing now).
 

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
Sorry. Signed up and using on mobile. Can’t find where to update my signature right now.

Pool is 15k gallons. I do already have the Taylor 2006 kit. I just read about SLAM. I’ll try that.
 

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
you didn't say what your FC levels were (or if they were at Zero), but after you are done slamming you might want to adjust your CYA up to the recommended levels.

I am in a similar situation to you and have passed the SLAM tests so the best answer I have is the darn UV rays during these hot months and my SWG being undersized for the job.

If you pass the SLAM, and CYA is ok... the only answers I have found (and someone can chime in ) is run the SWG longer (I am actually debating running 24/7 until the UV gets better later in the year) or supplement with chlorine (which I am doing now).
My levels right now are zero. I got them up to 1ppm 2 days ago by running a super chlorinate overnight but it has since returned to zero with 90% at 12 hours a day.

CYA is 55
 

Jason245

Well-known member
Jul 27, 2019
72
Fort Lauderdale FL
I would do a slam, I would also post your full test results for others to help.

Include your combined chlorine results (I am guessing it will also be an indicator you need to SLAM)
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
12,045
Evans, Georgia
Please post:
FC
CC
pH
TA
CH
CYA

Anytime you need to boost your FC fast you should be using liquid chlorine and then let your SWG maintain that level. The SWG works too slowly to bring you up from zero to x amount before either the sun or the algae take it away.

Maddie :flower:
 

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
you didn't say what your FC levels were (or if they were at Zero), but after you are done slamming you might want to adjust your CYA up to the recommended levels.

I am in a similar situation to you and have passed the SLAM tests so the best answer I have is the darn UV rays during these hot months and my SWG being undersized for the job.

If you pass the SLAM, and CYA is ok... the only answers I have found (and someone can chime in ) is run the SWG longer (I am actually debating running 24/7 until the UV gets better later in the year) or supplement with chlorine (which I am doing now).
My levels right now are zero. I got them up to 1ppm 2 days ago by running a super chlorinate overnight but it has since returned to zero with 90% at 12 hours a day.

CYA is 55
 

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
Added a bag of leslie's chlor boost yesterday and re-tested this morning
FC - 1ppm
CC - .5 ppm
CYA - 60
TA - 80
PH - 7.6
CH - 240
SALT - 2600

Heading out of town this weekend for a wedding. I'll do the SLAM using liquid chlorine on Monday when I get back. Thanks everyone.
 

Jason245

Well-known member
Jul 27, 2019
72
Fort Lauderdale FL
Added a bag of leslie's chlor boost yesterday and re-tested this morning
FC - 1ppm
CC - .5 ppm
CYA - 60
TA - 80
PH - 7.6
CH - 240
SALT - 2600

Heading out of town this weekend for a wedding. I'll do the SLAM using liquid chlorine on Monday when I get back. Thanks everyone.

You might need to add salt, don't know what your SWG specs say, but I would check.

This could also explain why your SWG isn't producing.
 

DrockDrg

Member
Sep 11, 2019
6
Port Orange, FL
Yea. I added a bag this morning. SWG recommends 2800 - 3200. This is the first time its read that low all month though. Previously its been staying pretty consistent at 2900. I also added some acid this morning to get the Ph down a little in preparation for doing the SLAM.
 

Patrickoleary

Well-known member
Apr 7, 2019
122
Greensburg,PA
Had exact same issue last month with my SWCG. I swore up and down that there had to be a problem with it. My water looked crystal clear.

I finally gave in and did the SLAM. Passed after a few days. SWCG has been running like a champ at only 20% and keeping my FCL around 7 since. Very happy with the SWCG now.
 
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