CC 4x Higher Than FC--->Keeps Climbing

Jun 20, 2020
16
Chesapeake Virginia
Hello all,

Brand new to the Forum! I have a 12000 gal in-ground vinyl lined liq bleach chlorinated pool. I switched to liq bleach from inline tri-chlor tabs about 2 months ago after reading through the Pool School. At first the switch was great. Within the past 2 weeks though, my CC keeps climbing higher and higher. Should I put some tabs back in the inline generator to raise my CYA a bit, then do a slam tomorrow? According to the Calculator if I am using it right, my slam target should be around 12, is that correct? I have a feeling I am doing the slams incorrectly. With the CC as high as it is right now, is it safe for us to swim? "that one buddy" say's it's fine due to the TC being safe, but my own personal interpretation of information on this site and elsewhere say's CC of 6 is not safe. Any help or advice to LOWER my CC would be greatly appreciated! Test results below.

As of today, my test results are:

PH:
7.4
Alk: 80
CYA: 20-30 (Taylor's can still barely see at 30, test strip says 20)
FC: 1.6
CC: 6
Water Temp: 75 deg F
Air Temp: 90 deg F
Location: Eastern Virginia
 
Last edited:

Mdragger88

Bronze Supporter
Jun 1, 2018
911
Hernando, Ms
Your fc is below the min for your cya & no where near SLAM Process levels which would be 12. There’s no in between on the cya test so you round up to 30.
what does your water look like ?
did u allow your sample to sit before testing for cc? That will lead to inaccurate results.
 
Jun 20, 2020
16
Chesapeake Virginia
Your fc is below the min for your cya & no where near SLAM Process levels which would be 12. There’s no in between on the cya test so you round up to 30.
what does your water look like ?
did u allow your sample to sit before testing for cc? That will lead to inaccurate results.
1. The water is clear, ever so cloudy in the deepest portion, but can still make out a coin on the bottom.
2. No. I am aware that the FC/CC test is inaccurate if done to slowly. So I test for CC directly after FC, and the whole test is complete within a timed 3 minutes from the point that the powder dissolves in step 1. Overall test time is usually 3 min 20 sec. Test completed twice, and compared to test strip values with a deviation of 10% from the Taylor values for CC/FC.
 
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Mdragger88

Bronze Supporter
Jun 1, 2018
911
Hernando, Ms
If cloudy @ all your fighting something- especially since your fc is below min.
Elevated cc is indicative of organics- they are high but the answer is more chlorine.
Also be sure nothing is dead anywhere - bird, frog, mouse...
You have only added liquid chlorine correct?
 
Jun 20, 2020
16
Chesapeake Virginia
What was the CYA at the time you switched from tabs to liquid?

Has the CYA recently gone down unexpectedly?

Have you used Jack's #2 copper and scale stuff?
1. It was hovering around 50-60 ppm. Lots of rain, making the switch to non-trichlor, and time I suppose have lowered it perhaps.
2. No it has just gradually been tapering down to about where it is now (20-30, 30 if rounding up) and holding.
3. I was using the forbidden "Leslies perfect weekly" every other week until I made the switch to this sites method and threw it out. So haven't used in about 2 months.
 
Jun 20, 2020
16
Chesapeake Virginia
If cloudy @ all your fighting something- especially since your fc is below min.
Elevated cc is indicative of organics- they are high but the answer is more chlorine.
Also be sure nothing is dead anywhere - bird, frog, mouse...
You have only added liquid chlorine correct?
Skimmer is clean, pump basket is clean, floors and walls are squeaky clean. At some point in the past few weeks as I've noticed the CYA getting lower, I'd drop a tri-chlor tab in the basket to help bring it up. Haven't done that in over 2 weeks for sure though, as I cleaned the garage then and put em away.
 

JamesW

TFP Expert
Mar 2, 2011
19,783
You might have gotten some bacteria that eats cyanuric acid and turns it into ammonia.

Complete a full SLAM.

If it is ammonia, you will typically see the pH and TA drop as the chlorine is added.
 
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Jun 20, 2020
16
Chesapeake Virginia
also here’s a video explaining how to slam to clear up any confusion
Thank you. I have already watched that and read the guide, but I am guessing I am doing something wrong or missed something while reading based off of my results. I'm a mech engineer and tend to overthink/complicate things. Some questions I have that the video and guide left me wondering:

When doing the SLAM, is it better that both the skimmer and floor inlet are open equally at the Jandy valve, or skewed to one way or the other?

In the written guide it says vacuuming daily, but doesn't specify vacuuming to waste or filter, (I assume filter, as waste would lose water and hence precious chlorine), but which do you recommend?

Once the FC actually maintains at the SLAM level, (which I am having trouble accomplishing), and the CC drops to zero, how long does it usually take to taper down to the recommended swimming levels?

During the SLAM process, how often or at all should I backwash filter?
 
Jun 20, 2020
16
Chesapeake Virginia
You might have gotten some bacteria that eats cyanuric acid and turns it into ammonia.

Complete a full SLAM.

If it is ammonia, you will typically see the pH and TA drop as the chlorine is added.
The pH and TA HAVE been dropping after adding chlorine! Okay, onto something here. So full slam. Maintain FC at 12 until CC hits zero and no FC loss overnight, correct?
 
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Mdragger88

Bronze Supporter
Jun 1, 2018
911
Hernando, Ms
The perfect weekly is a phosphate remover - I don’t think it would have any effect now.
If ammonia is the problem the answer is still liquid chlorine
At any rate u need to do a SLAM Process
Follow to the letter -
-You can configure your inlets however u like
-Vacuum to filter
- backwash when pressure rises 25% over clean pressure
it is safe to swim when:
Ph is 7.2 to 7.8
FC is above minimum
FC is below shock level
Water is clear
 
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Reactions: Avogadrosnumber
Jun 20, 2020
16
Chesapeake Virginia
The perfect weekly is a phosphate remover - I don’t think it would have any effect now.
If ammonia is the problem the answer is still liquid chlorine
At any rate u need to do a SLAM Process
Follow to the letter -
-You can configure your inlets however u like
-Vacuum to filter
- backwash when pressure rises 25% over clean pressure
it is safe to swim when:
Ph is 7.2 to 7.8
FC is above minimum
FC is below shock level
Water is clear
Thank you!
 

Mdragger88

Bronze Supporter
Jun 1, 2018
911
Hernando, Ms
The pH and TA HAVE been dropping after adding chlorine! Okay, onto something here. So full slam. Maintain FC at 12 until CC hits zero and no FC loss overnight, correct?
Cc of .5 or less
& crystal clear water - no clouds when brushing
Be sure to do a proper Overnight Chlorine Loss Test
The more frequently u bring to slam level the faster you will hit all 3 criteria.
 
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Jun 20, 2020
16
Chesapeake Virginia
Cc of .5 or less
& crystal clear water - no clouds when brushing
Be sure to do a proper Overnight Chlorine Loss Test
The more frequently u bring to slam level the faster you will hit all 3 criteria.
Will do! Should I keep a tri-chlor tab in the inline chlorinator or skimmer while slamming to maintain CYA at it's current low level? Or just leave them out of it?
 
Jun 20, 2020
16
Chesapeake Virginia
Also be sure & clean your testing vial w/ a little bleachy water, rinse & dry it well just to be sure there’s no interference affecting your tests. 😊
I'm also going to order the TF-100 to have as a second test kit to compare values with. Some of my reagents are running low for the Taylor kit, so I'll just switch over to it fully when they run out.
 
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