Trouble Raising Chlorine

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
You can use the PoolMath APP (Effects of Adding) to help you with the amount of salt required to increase to a new target. But be sure to test your salt level with a good kit (i.e.. Taylor K-1766) and don't just take the cell's word for it. While the cell needs to sense a reasonable salt level, their accuracy can be off.

Your FC is definitely low, so increase with liquid chlorine right away. Your CC level is also elevated. You might consider doing an Overnight Chlorine Loss Test to ensure algae isn't trying to grow.
Thanks for sticking with me this far. Yesterday evening I added a gallon of bleach. By 7:30 FC was 6 and CC was 1. I checked as soon as I woke today and FC was 4.4 with CC .4. I also added salt as my reading was down to 2400. I’ve had my salt cell off since last night. Just got home and tested, FC dropped to 2, CC .4.

I will turn SWG back on this evening. Is it odd I’ve love 2.4ppm FC today?

 

Texas Splash

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Jun 22, 2014
33,434
Texas, San Antonio/Marion, South-Central Area
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Surface
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The FC is definitely something to watch. I'm assuming 7:30 pm last night was dark or very close to it for you up there? Was the sun on the water when you took your morning sample? An FC of 2 is certainly low, so it's good you caught it right away. I'd add enough liquid chlorine to bump the FC up to 6-8 PPM and let the SWG run now. I know your season is getting short, but we do want the water algae-free at closing. If you find yourself concerned about FC loss again and decide to do another OCLT, do it with a starting (nighttime) FC of about6-8 ppm, leave the SWG off, and check again in the morning before light hits the water.

Something else. For your FC testing, you can do it as follows:
10ml water sample size with ONE generous scoop of powder. Mix until clear and divide result in half. Example: 16 drops equals an FC of 8.
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
The FC is definitely something to watch. I'm assuming 7:30 pm last night was dark or very close to it for you up there? Was the sun on the water when you took your morning sample? An FC of 2 is certainly low, so it's good you caught it right away. I'd add enough liquid chlorine to bump the FC up to 6-8 PPM and let the SWG run now. I know your season is getting short, but we do want the water algae-free at closing. If you find yourself concerned about FC loss again and decide to do another OCLT, do it with a starting (nighttime) FC of about6-8 ppm, leave the SWG off, and check again in the morning before light hits the water.

Something else. For your FC testing, you can do it as follows:
10ml water sample size with ONE generous scoop of powder. Mix until clear and divide result in half. Example: 16 drops equals an FC of 8.
Yes. No sun on pool in the evening or morning. So last night FC was 8, so higher than the 6 you mentioned. This morning, before sun was 4.4. Today after work was 2.
I will bring it up tonight, test, and see what tomorrow brings. Swg is on now.
 

Texas Splash

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Jun 22, 2014
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So last night FC was 8, so higher than the 6 you mentioned. This morning, before sun was 4.4.
Yikes. Bummer. :( That's a major drop and an OCLT fail for sure. I'll be curious to see w hat your numbers look like tomorrow. Be sure the water is mixed well before grabbing each water sample.
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Yikes. Bummer. :( That's a major drop and an OCLT fail for sure. I'll be curious to see w hat your numbers look like tomorrow. Be sure the water is mixed well before grabbing each water sample.
Ok. So this morning at 9:30 FC was 4.4 and CC .6.
Just now, FC 3.0 and CC.4. SWG has been running all day. I set it based in the recommendations to raise FC to 6, yet FC has gone down.

SWG is flashing high salt despot the fact my salt was down to 2400 the other day. I have it now at 3200.

just seems I can’t hold chlorine. My cya is around 70. Honestly I hate that test. It I can see even a speckle of the black I add more to the test.

it just seems odd that I am adding chlorine every day.

PoolMath Logs
 

Texas Splash

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Jun 22, 2014
33,434
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Krista, after reviewing your test logs, I think you will have to run a SLAM Process. :( You're simply losing just too much FC each day & night. A couple day ago you barely passed an OCLT, but your FC level is simply falling too low. With days getting shorter and nighttime temps starting to fall, a SLAM could be in your favor. I would lower your pH just a little to about 7.2, then increase and maintain an FC of 28 based on your CYA of 70. 28 would be your SLAM level. It's important to maintain that level with liquid chlorine as best as you can throughout the day and before calling it a night. Be sure to inspect and brush all the areas of the pool as noted on that SLAM page link. This is beneficial to you since I'm assuming you'll be closing in a month or so. Now's the time. Do you have any questions?
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Krista, after reviewing your test logs, I think you will have to run a SLAM Process. :( You're simply losing just too much FC each day & night. A couple day ago you barely passed an OCLT, but your FC level is simply falling too low. With days getting shorter and nighttime temps starting to fall, a SLAM could be in your favor. I would lower your pH just a little to about 7.2, then increase and maintain an FC of 28 based on your CYA of 70. 28 would be your SLAM level. It's important to maintain that level with liquid chlorine as best as you can throughout the day and before calling it a night. Be sure to inspect and brush all the areas of the pool as noted on that SLAM page link. This is beneficial to you since I'm assuming you'll be closing in a month or so. Now's the time. Do you have any questions?
Thank you. I’ve been reading and was feeling this was my next step. I’ll be taking a FC test in about an hour to see what happen again over night. I’ll start that process this evening. So I need to leave the cover off for this whole process?
 

Texas Splash

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Jun 22, 2014
33,434
Texas, San Antonio/Marion, South-Central Area
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Surface
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Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Good morning. Yes, it's best to just leave the cover off. That way the combined chlorine will get eliminated by the sun quickly. Once you add the chlorine, leave the SWG off and let the chlorine do all the work - along with your normal cleaning chores. Your water wasn't bad looking, so hopefully you will find that once the chlorine level hits 28 it doesn't crash too badly throughout the day. It should stabilizer fairly soon. But keep an eye on it. I'm sure it will be fighting some organics or something.
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Yesterday, I measured my free chlorine at 2.0 and my combine chlorine a .6. My salt reading was showing 2800. I use the Taylor K Dash 2006C test kit. My salt cell is flashing for high salt. I checked the hours on my cell and it is showing 2000 hours so plenty of life left in my cell. Yesterday evening I ran my SWG on super chlorinate for three hours. This morning when I tested I am still showing free chlorine at 2.0 in cc at .6. I am really feeling like I need to add some salt to the pool. I have a Pentair Intellichlor IC 40. My concern is is that I’ve read to go buy whatever your salt cell is saying. Any advice or recommendations would be appreciated.

the pool is crystal clear.

Alk 85-90 adjusted for CYA
ph 7.4
CH 250

Fiberglas pool
Try to hit Slam target. I’ve put in a bit more than my log shows and I’m not to 28 yet! Do I keep going. Not sure how long it takes but it’s been over an hour. I also have a basic question when reading my combine chlorine test. Everything turns white but if I leave it sitting on my table for a minute or two it turns pink again I’m assuming I should’ve just thrown it out by now but I want to make sure that I’m not miss reading my test
 

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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,434
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Yes, add more chlorine to be sure you reach the required FC level. The fact it's dropping means the chlorine is fighting something in the water. As for the cc test, that (and the FC) will begin to change back to red if you let it sit. Take your reading right away and dump it.
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Yes, add more chlorine to be sure you reach teh required FC level. The fact it's dropping means the chlorine is fighting something in the water. As for teh cc test, that (and the FC) will begin to change back to red if oy let it sit. Take your reading right away and dump it.
Ok. So you think it’s fighting something even though I’m not seeing my combine chlorine go up
 

Texas Splash

Mod Squad
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Jun 22, 2014
33,434
Texas, San Antonio/Marion, South-Central Area
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So you think it’s fighting something even though I’m not seeing my combine chlorine go up
As the evening sun it setting, there's no doubt the chlorine is fighting something. FC disappears to two things - sun & organics. You won't always see a spike in CC level, so don't feel like you're missing something. The drop in FC level is your big key indicator.
 

KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
As the evening sun it setting, there's no doubt the chlorine is fighting something. FC disappears to two things - sun & organics. You won't always see a spike in CC level, so don't feel like you're missing something. The drop in FC level is your big key indicator.
Ok. I just added quite a bit more. Given that I know this should put me well over 25 is it that important that I test again this evening or can I test first thing tomorrow morning?

 
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KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Lots of loss overnight. Added more chlorine this Am. Pool is crystal clear as always. Could this be in my pipes?

 

Mdragger88

Bronze Supporter
Jun 1, 2018
2,979
Hernando, Ms
Pool Size
26000
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Vinyl
Chlorine
Salt Water Generator
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Intex Krystal Clear
SLAM Process should take care of anything in the plumbing since there’s flow.
Check/scrub all nooks & crannies- light niches, drain covers, ladders (hand rails), skimmer throats & weir doors (their foam), water features, the under side of cover, do u have a heater?
It’s hiding somewhere eating your fc.
 
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KristaM78

Well-known member
Jun 29, 2021
56
Illinois
Pool Size
11200
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Now you know for sure there is organic growing in the pool. Inspect, inspect, inspect. :)
Ok. One final question for you. I always feel like I suck at testing my CYA level. Let’s assume my CYA level is higher than 75. I know you would suggest a partial drain. At this point I’ve already dumped so much chlorine in. Given the amount of chlorine that I’m putting in and chlorine loss that I’m having I feel like I could make a reasonable assumption that my CYA is not excessively high or I would not be losing chlorine like I am. Is that a reasonable assumption? I’m just wondering if I need to bring my free chlorine up well over 30 to be certain.
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
2,979
Spring Valley, NY
Ok. One final question for you. I always feel like I suck at testing my CYA level. Let’s assume my CYA level is higher than 75. I know you would suggest a partial drain. At this point I’ve already dumped so much chlorine in. Given the amount of chlorine that I’m putting in and chlorine loss that I’m having I feel like I could make a reasonable assumption that my CYA is not excessively high or I would not be losing chlorine like I am. Is that a reasonable assumption? I’m just wondering if I need to bring my free chlorine up well over 30 to be certain.
Or if you're questioning the CYA, if it's indeed higher then you're not reaching slam per the CYA level so that can also be a factor why the FC gets consumed and isn't starting to hold better.
 
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