Chlorine level too high?

SumoSimo

Member
Jun 3, 2021
17
Virginia
Hi there,

I just moved into a home with a pool, and I didn't really have much time to care for the pool. I'm trying to measure the chlorine level in my pool, and I am doubting whether or not I'm doing it correctly. For context, a pool company came out just yesterday and SLAMed the pool.

I'm using the Taylor K-2006 testing kit, and I followed the instructions for measuring chlorine. I filled up the large tube with sample pool water up to the 25 mL mark and added two scoops of the powder (R-0870). The water turned pink, and I started adding the drops (R-0871). After 200 drops, it still didn't turn colorless. If I'm not doing anything wrong, this would indicate a pool with over 40 ppm of chlorine and 30-50 ppm of CYA (according to the pool company).

I've attached a photo of the large tube for reference. To me, it doesn't look colorless, but I'm doubting myself since it's my first time.

I am also attaching a photo of the seven or so chlorine tablets the pool company added to the skimmer.

What should I do? Many thanks.
 

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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,498
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
If you have a gas pool heater the acid in those chlorine tablets in your skimmer will destroy your heater. You need to safely remove them ASAP.

What your pool company did was not the TFP SLAM Process. Not even close.

In the future use a 10ml sample for the FAS/DPD test and multiply the drops by 0.5. You will use a lot less reagent and enrich Taylor less.

Post a complete set of test results in the format...

FC
CC
pH
TA
CH
CYA

How does your pool water look? Post a pic of your pool.

Please create your signature with details of your pool and equipment.
 
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SumoSimo

Member
Jun 3, 2021
17
Virginia
It looks like I have this gas heater. I have removed the chlorine tablets per your recommendation.

I take it that my chlorine test is valid? I'll definitely be using 10 mL next time.

Here are my chemical levels:

FC - Over 40 ppm (could not get it to turn colorless even after 200 drops)
CC - Could not calculate because sample would did not become colorless
pH - 8.0
TA - 100
CH - 400
CYA - 30-40

I have attached a couple pictures showing what the pool looks like currently. I have also attached additional pictures of the pool equipment.
 

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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,498
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Note that at a FC greater then 10 your pH is not valid. So don’t adjust your pH right now.

Assume your CYA is 40 and your SLAM FC is 16. Let your FC drift down to 16 and maintain it there with liquid chlorine. Then see when you pass the three exit criteria of the SLAM Process.

Just test your FC and CC during the SLAM Process
 
Last edited:
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HermanTX

Gold Supporter
May 20, 2020
2,541
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
Understood, I'll keep an eye on it throughout the week.
You may want to invest in a speed stirrer. It really helps to get consistent results on FC, CC, TA and CH tests. Lets you focus on counting drops and not trying to swirl with one hand while your are squeezing drops with the other hand.
 

SumoSimo

Member
Jun 3, 2021
17
Virginia
I just measured FC/CC again this morning using the 10 mL mark, and this time it was obvious when the sample became colorless. FC is 16.5 and CC is 0.5. I'm baffled as to why FC dropped from >40 to 16.5. This leads me to believe that I did something wrong when measuring FC the first time, but I'm uncertain if that's really the case since I followed the instructions exactly and the photo shows otherwise.
 

HermanTX

Gold Supporter
May 20, 2020
2,541
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
I just measured FC/CC again this morning using the 10 mL mark, and this time it was obvious when the sample became colorless. FC is 16.5 and CC is 0.5. I'm baffled as to why FC dropped from >40 to 16.5. This leads me to believe that I did something wrong when measuring FC the first time, but I'm uncertain if that's really the case since I followed the instructions exactly and the photo shows otherwise.
There could be some error on counting or swirling, or even drop size coming out of the bottle, etc. but you will gain confidence as you gain experience. Just keep testing daily can consider that speedstirrer mentioned earlier.
 

Bperry

Gold Supporter
Aug 20, 2020
862
Knoxville, TN
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
There could be some error on counting or swirling, or even drop size coming out of the bottle, etc. but you will gain confidence as you gain experience. Just keep testing daily can consider that speedstirrer mentioned earlier.
Wasn’t there some Taylor advice that said after so many drops, the test becomes less unreliable? I wanna say it was something like 30-ish drops, or it might have been 30ppm?
 

HermanTX

Gold Supporter
May 20, 2020
2,541
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
Wasn’t there some Taylor advice that said after so many drops, the test becomes less unreliable? I wanna say it was something like 30-ish drops, or it might have been 30ppm?
I read through the Pool & Spa Water Chemistry booklet that comes with the K-2006 test kit and I could not find anything regarding unreliable with > x drops. I even looked at FAQs and that was not addressed. Maybe someone else has additonal info.
 

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revitup

Gold Supporter
Bronze Supporter
Nov 30, 2019
633
Pawleys Island, SC
Pool Size
8500
Surface
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Chlorine
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With each drop comes some tolerance and so some small potential error. As more drops are added that error tolerance is cumulative. At some level of drops that error becomes significant for testing purposes. Maybe that level is 30 drops? No idea.
 

SumoSimo

Member
Jun 3, 2021
17
Virginia
A week has passed, and I'm a lot more used to testing now. I brought the pool back to normal levels after passing the OCLT. Here are my readings as of today:

FC - 3
CC - 0
pH - 7.7
TA - 90
CH - 325
CYA - 40

Based on the page that explains ideal pool levels, it looks like my TA is within the acceptable maximum range, and my CH is within the acceptable minimum range. Everything else seems to be where they should be.