Testing concerns with the Taylor K-2006C kit...

[24Brix]

Hi, all! I’m really glad to have found this community! Apologies for the long post. I figure this is one of those times where TMI can be a good thing.

I’m a 20-year owner of a 35-years old 28,000 gallon Anthony in-ground plaster pool with a DE filter — all original or original-equivalent parts but the plaster has seen better days, lol. I’ve been struggling with water chemistry this season for the first time ever. The pool is located in the mid-Atlantic (Frederick, MD), uses a mesh safety cover in the winter, and is (and has always been) surrounded by our neighbors’ huge pine trees. The water is always dirty in the spring but, in the past, we’d circulate the water for a month in April, uncover in May, rake out the pine needles and whatever else got past the cover, vacuum/backwash it a few times, hit it with 5 or 6 lbs. of cal-hypo and be good to go. Not this year.

We had to leave the cover on until the beginning of June because we lost a bunch of fencing in a storm. I went through my usual process of adjusting the pH to 7.2 and shocking but it didn’t budge. No FC the next morning. I did it again the next day for a total of 10 lbs. of cal-hypo and it still didn’t budge. Dip sticks suggested 10+ TC and 0FC. I knew I was in a hard chlorine lock so I ordered a Taylor K-2006C test kit as recommended here (before I became a member) from Amazon. It was going to take 5 days to arrive so I went to a couple pool stores to confirm those sad little dipsticks. Their numbers for chlorine were all over the map but most of the others were pretty much in agreement. Two recommended all sorts of additions but I was skeptical. One store recommended shocking with 11 gallons of 12.5 liquid chlorine and doing nothing else until that was resolved (pH was fine) which is sort of in line with what I was seeing on the threads here. So I did that. Still no free chlorine the next morning. But now the water is blue though somewhat milky, especially in the deep end. I can see the drain in the bottom at 9’ but it’s hazy. There have been no chloramine odors at any point throughout all of this. I have been brushing, vacuuming, and backwashing as needed throughout. Jump ahead to today...

My Taylor K-2006C test kit arrived. Reagents expire in 2023. The water is still blue and cloudy. Test results are as follows:

FC = 14
CC = 1.5
Calculated TC = 15.5
pH = 7.2
TA = 150
CH = 220
CYA = <20 (the pool stores had called it 1, 5, and 5, respectively.

So where do I go from here? What else do you need to know that I’ve omitted? I’ve never been in the situation where FC exceeds CC and I don’t understand how it’s even possible. Final notes: the dip-sticks still say I’m locked. A pool store ran my sample through their system and says I’m locked worse than ever they want me to add 38 gallons of 12.5 chlorine. I’m following the Taylor instructions carefully, exactly, and quickly. I’m at a loss for what to do next.

Thanks so much for your collective insight! It seems I’ve had it easy for a long time and I’m *super* frustrated now. Sigh...

 

[mknauss]

Welcome to the forum!
Follow the SLAM Process. Read the article. You need to get your CYA to 30 ppm.
Is the CYA test clear or cloudy?
Once you confirm how much CYA you need to start adding via the sock method, you then start adding liquid chlorine to raise your FC to SLAM level based on your planned CYA level - see FC/CYA Levels. You then test and add more liquid chlorine every few hours.

There is no such thing as chlorine lock. That is a pool store term.

I suggest you read ABC's of Pool Water Chemistry.

 

[mknauss]

 

[Jimrahbe]

24,

Normally, when the pool store says you have chlorine lock, you have a CYA level of way over 100.. So, on the surface that makes no sense.

Tell us how you are running the CYA test.

Thanks,

Jim R.

 

[24Brix]

24,

Normally, when the pool store says you have chlorine lock, you have a CYA level of way over 100.. So, on the surface that makes no sense.

Tell us how you are running the CYA test.

Thanks,

Jim R.

Thanks for responding, Jim. I did the CYA test using the K-2006C kit. Mix the sample with testing solution and fill the tube until the little black dot at the bottom is obscured by the cloudy solution. The “max fill” line indicates a CYA of 20. But the black dot is still plainly evident even then so my CYA must be substantially less than that. Tests from two different pool stores claim it’s either at 1 or 5 which is certainly under 20.

I found a local vendor that sells the liquid Biogard 100 stabilizer — 1 gallon adds 32ppm of CYA to 10,000 gallons. But they advised against using it saying the TC could be causing an artificially low CYA reading. They want me to eliminate my CC and bring the chlorine levels back to normal range before adding CYA and potentially overshooting. And *this* advice is one of the many reasons I am here.

 

[mknauss]

saying the TC could be causing an artificially low CYA reading

Chlorine level has no effect on the CYA test.

 

[24Brix]

Welcome to the forum!
Follow the SLAM Process. Read the article. You need to get your CYA to 30 ppm.
Is the CYA test clear or cloudy?
Once you confirm how much CYA you need to start adding via the sock method, you then start adding liquid chlorine to raise your FC to SLAM level based on your planned CYA level - see FC/CYA Levels. You then test and add more liquid chlorine every few hours.

There is no such thing as chlorine lock. That is a pool store term.

I suggest you read ABC's of Pool Water Chemistry.

Thanks! I’ve read a lot here and watched many of the videos and everything has been very informative and worthwhile. I’m still confused by my test results, though.

The Taylor CYA test is essentially clear. I know my CYA is low but was advised by a pool store not to raise it yet since their test indicates my CC is at 11.4 and may be masking a normal CYA level. But even if that’s true (I’ve not heard of it), their CC results are completely at odds with the Taylor K-2006C FAS-DPD results. My results, as noted in the OP, repeatedly show FC at 14 and CC at 1.5 when I tested at various times today.

I found a local source for Biogard 100 liquid stabilizer and can get some tomorrow if need be.

Thanks again for you response!

 

[mknauss]

We only believe your test results.

 

[24Brix]

Chlorine level has no effect on the CYA test.

Thanks. In that case, I’ll pick up some liquid stabilizer tomorrow and calculate the dose needed to bring the pool up to 30.
Can you help me understand how I can have a FC of 14 and still have a CC of 1.5? It does not compute for me. I haven’t encountered it before and it feels upside down.

I’ve got 40 gallons of 12.5 liquid chlorine ready to go for a SLAM to try to get the water totally clear again. The pool store says my FC is 1 and my CC is 11.4; the Taylor K-2006C says my FC is 14 and my CC is 1.5. So I’m not sure whether to put more chlorine in tonight or not. And if I do, how much I should hit it with. ~15ppm according to my test or ~114ppm according to theirs. Sigh...

 

[mknauss]

CC is the reaction of FC with ammonia based organics. The CC is eradicated via UV from the sun impacting the surface of the pool water.

There is no reason you cannot have a FC of 14 and a CC of 1.5.

Follow the SLAM Process. The SLAM level FC is based on CYA. When you add the CYA to get to 30 ppm, then you target FC of 12 ppm and maintain that.

 

[Msch99]

Ignore pool store tests. Even as a newbie yours are more accurate. These folks will help you and question any results that look a bit off. RELAX! You are in good hands.

 

[Oly]

What sample size did you use for the FC test and how many drops to clear?

 

[24Brix]

What sample size did you use for the FC test and how many drops to clear?

I did tests using both the 25ml and 10ml sample sizes.

I used a 25ml sample for my first pass and it took 70 drops to clear for a FC of 14. Then 5 drops for a CC of 1.

The 10ml sample took 26 drops to clear for a FC of 13. Then 3 drops for a CC of 1.5. This was the test I used periodically throughout the day with consistent results. (I figured I might as well use less reagents, at least until I’m closing in on where the levels should be.)

In both cases I completed the CC titration quickly after the FC went to clear. And in both cases, after the CC titration was complete, the colorless solution started drifting back into pink in less than a minute. But I believe that’s normal.

Thanks in advance for your insight!

 

[Deb04]

There's no reason not to use the liquid stabilizer, other than that it is expensive as compared to granular stabilizer. If you go to Walmart, you can get 4 lbs of stabilizer for about $18. Put the amount you need in a cheap knee-high or sock, tie it off and place it in front of the return without it touching the pool side. I tie it to the pole for the brush and hang it in front of the return. After about 30-60 minutes, go out and squeeze the sock. It will quickly dissipate.

 

[24Brix]

There's no reason not to use the liquid stabilizer, other than that it is expensive as compared to granular stabilizer. If you go to Walmart, you can get 4 lbs of stabilizer for about $18. Put the amount you need in a cheap knee-high or sock, tie it off and place it in front of the return without it touching the pool side. I tie it to the pole for the brush and hang it in front of the return. After about 30-60 minutes, go out and squeeze the sock. It will quickly dissipate.

Brilliant! Thanks! I wasn’t sure how caustic it is given it’s an acid and thought I might need to find a chemically resistant mesh bag or something for that approach to work. But it sounds like anything with a tight weave might be just fine.

 

[BassPlayingDude]

I have found that "skimmer socks" work great for this purpose

 

[mguzzy]

Thanks! I’ve read a lot here and watched many of the videos and everything has been very informative and worthwhile. I’m still confused by my test results, though.

The Taylor CYA test is essentially clear. I know my CYA is low but was advised by a pool store not to raise it yet since their test indicates my CC is at 11.4 and may be masking a normal CYA level. But even if that’s true (I’ve not heard of it), their CC results are completely at odds with the Taylor K-2006C FAS-DPD results. My results, as noted in the OP, repeatedly show FC at 14 and CC at 1.5 when I tested at various times today.

I found a local source for Biogard 100 liquid stabilizer and can get some tomorrow if need be.

Thanks again for you response!

Brix.. Howdy and welcome to the Forum!

Your test results make perfect sense. an FC of 14 and a CC of 1.5... that just means there is bio activity consuming the chlorine and the by product is represented as CC.when you get your CC below .5, that usually means there is nothing substantial going on. You can have clear water and still have a CC reading above 1.0, it just means the algae or bacteria hasn't populated enough to see it.. but the CC reading tells you its there.

Based on your CYA test, it sounds like you essentially have nothing there. Use the effects of Adding feature of the PoolMath to calculate how much you will need to add to get to 30. You don't want to go any higher if you are going to SLAM. If you follow this FC/CYA Levels, you'll see what I mean.. more CYA means a higher SLAM FC.

And lastly, Stop running back to the pool store for advice. Their recommendations are going to be different that ours. Pool Store methodology is based on pool standards that are outdated. They just don't know it yet. If you are interested there is a whole section of the forum that discusses the science behind how the TFP protocol works. But for now, just follow the recommendations on this site. We are all consistent in our advice.. and we almost always don't agree with what the pool store says. And I can guarantee we are cheaper.

 

[mguzzy]

I did tests using both the 25ml and 10ml sample sizes.

I used a 25ml sample for my first pass and it took 70 drops to clear for a FC of 14. Then 5 drops for a CC of 1.

The 10ml sample took 26 drops to clear for a FC of 13. Then 3 drops for a CC of 1.5. This was the test I used periodically throughout the day with consistent results. (I figured I might as well use less reagents, at least until I’m closing in on where the levels should be.)

In both cases I completed the CC titration quickly after the FC went to clear. And in both cases, after the CC titration was complete, the colorless solution started drifting back into pink in less than a minute. But I believe that’s normal.

Thanks in advance for your insight!

You can also use a 5 ml sample and change your multiplier accordingly (1 drop =1ppm). Its useful when you are in the heat of a SLAM since you don't need the precision of a 10 or 25 ml sample. Also a testing error results, when you approach 50 drops of reagent in the drop based tests.

Yes, the sample will turn back to pink if you let it sit. That is caused by a reaction with the air if I recall my college chem lessons.

 

[24Brix]

Brix.. Howdy and welcome to the Forum!

Your test results make perfect sense. an FC of 14 and a CC of 1.5... that just means there is bio activity consuming the chlorine and the by product is represented as CC.when you get your CC below .5, that usually means there is nothing substantial going on. You can have clear water and still have a CC reading above 1.0, it just means the algae or bacteria hasn't populated enough to see it.. but the CC reading tells you its there.

Based on your CYA test, it sounds like you essentially have nothing there. Use the effects of Adding feature of the PoolMath to calculate how much you will need to add to get to 30. You don't want to go any higher if you are going to SLAM. If you follow this FC/CYA Levels, you'll see what I mean.. more CYA means a higher SLAM FC.

And lastly, Stop running back to the pool store for advice. Their recommendations are going to be different that ours. Pool Store methodology is based on pool standards that are outdated. They just don't know it yet. If you are interested there is a whole section of the forum that discusses the science behind how the TFP protocol works. But for now, just follow the recommendations on this site. We are all consistent in our advice.. and we almost always don't agree with what the pool store says. And I can guarantee we are cheaper.

Thanks! I think I see what you’re saying and it makes sense. My analogy’s not perfect but I guess you could say I’m using FC to burn organics like a car uses oxygen to burn gas. And CC us the exhaust. I’ve only been into this new way of thinking about pool chemistry for a few days and, when it comes to chlorine, I still have a tendency to slip back into the oversimplified “everything’s good if TC and FC are the same” mentality. But the test kit gives me a much higher-res view into what’s really going on with the C’s and the CYA. I expect a 0 CC will be relatively uncommon. There will always be some amount of CC no matter what thanks to pollen, random detritus I miss, even junk that washes in with the rain or rides in with the vacuum hose. I’m just not used to seeing it accurately represented numerically, lol.

I do wonder if I also have a filtration problem as well. By day, the water is cloudy in the deep end. Tonight, when I kicked on the pool lights for the first time this year, discrete particles are readily apparent to the eye even though we run the filter 24/7. The DE grids are new but I wonder if there’s a leak somewhere. Or if the tree pollen is really just that bad still... First things first, I need to get that CC down to .5 or less. And get the CYA up to 30.

 

[mguzzy]

I do wonder if I also have a filtration problem as well. By day, the water is cloudy in the deep end. Tonight, when I kicked on the pool lights for the first time this year, discrete particles are readily apparent to the eye even though we run the filter 24/7. The DE grids are new but I wonder if there’s a leak somewhere. Or if the tree pollen is really just that bad still... First things first, I need to get that CC down to .5 or less. And get the CYA up to 30.

Lets not get ahead of ourselves. Get your chems in line and get your CYA up to the right level. You could just be seeing the dead algae from the elevated FC.. that's good. But its being produced faster than your filter can take it out as evidenced by the high CC. Another member use to use his pool light at night as an early indicator of a impending algae bloom, once he realized what it was. I'll let @Newdude tell you his sea chantey stories on that one.