Chlorine level too high?

[SumoSimo]

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).

What should I do? Many thanks.

 

[ajw22]

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.

 

[SumoSimo]

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

 

[ajw22]

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

 

[SumoSimo]

Understood, I'll keep an eye on it throughout the week.

 

[HermanTX]

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.

Taylor Technologies 9265 SpeedStir Magnetic Stirrer Start-Up Pack with Stir Bar and Batteries: Swimming Pool Liquid Test Kits: Amazon.com: Industrial & Scientific

Taylor Technologies 9265 SpeedStir Magnetic Stirrer Start-Up Pack with Stir Bar and Batteries: Swimming Pool Liquid Test Kits: Amazon.com: Industrial & Scientific

smile.amazon.com

 

[SumoSimo]

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]

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]

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]

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.

 

[revitup]

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]

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.

 

[Jimrahbe]

S,

Well, almost... with a CYA of 40 your FC target should be 5 to 7 ppm.. Your very minimum is 3. I always try to keep my FC at my Target or higher.. I treat the minimum as a cliff that I never want to fall off.

See this chart... Chlorine / CYA Chart - Trouble Free Pool

Thanks,

Jim R.