The cya/chlorine chart calls for higher fc ppm than I am used to seeing. For instance target goal for cya at 40 is 5ppm. The KemTek liquid chlorine 10% box that I opened today says don't swim until the ppm are 4 or below. That also reflects other "normal " ranges I see on my test kit and published. What am I not understanding. Thanks, Jim
Confused
- Thread starter Bbbjim
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At the bottom of the chlorine/cya chart page there is a link to a thread that discusses the origin of the chart and the numbers.
There is a possibility that the KemTek folks and whoever makes your test kit does not fully understand the CYA/FC relationship. SOME of that FC is being held in reserve by the CYA. I keep my CYA at 50 to 60 and my "target" is 8 by wehich I still lose almost 4ppm daily in summer. I don't think 40 cya is gonna be sufficient for your "mild" summers!
The "normal" and "safe" ranges used in the industry are true... IF there is no CYA in the water. CYA protects chlorine from sunlight but also significantly buffers the strength of chlorine. This is something only a few in the industry are slowly starting to accept, most follow the old rules with no thought to the CYA level.
Because of the buffering effects the recommended levels are roughly the same as 0.2 ppm of unbuffered chlorine, which is why even with the higher FC levels our pools feel more comfortable and less like a stereotypical chlorine pool.
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Because of the buffering effects the recommended levels are roughly the same as 0.2 ppm of unbuffered chlorine, which is why even with the higher FC levels our pools feel more comfortable and less like a stereotypical chlorine pool.
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WONDERFUL question and awesome answers! Does this put your mind at ease? The levels suggested here at TFP are science based as well as "real life" tested.
Let us know if there are any other questions you might have.
Kim :cat:
Let us know if there are any other questions you might have.
Kim :cat:
Wow, thanks for the quick replies. Hard to break free of "conventional" ideas. Reading, learning and wishing I had stared at the girls less and listened more in chemistry class.
Im using a Taylor basic pool OTO test kit. Tha max total chlorine level is 5ppm. I have a TF-100 test kit on order and wondering if it will allow me to read higher levels of FC?
My CYA tested (at Leslie's ) at 100, so I am planning a partial pool drain if we get some cooler weather next week and I get my new test kit. From what I have learned so far, I should bring the CYA down to where I can maintain FC above the indicated minimal levels on the chart and minimize Cl loss to sun.
Form Woodyp's post I prolly should bring the CYA down to 50 - 60 and work with that as a good starting place. Jim
Im using a Taylor basic pool OTO test kit. Tha max total chlorine level is 5ppm. I have a TF-100 test kit on order and wondering if it will allow me to read higher levels of FC?
My CYA tested (at Leslie's ) at 100, so I am planning a partial pool drain if we get some cooler weather next week and I get my new test kit. From what I have learned so far, I should bring the CYA down to where I can maintain FC above the indicated minimal levels on the chart and minimize Cl loss to sun.
Form Woodyp's post I prolly should bring the CYA down to 50 - 60 and work with that as a good starting place. Jim
How does your pool look? At this point we would really like to see some pictures.
To answer your questions:
Yes, the TF kit has the ability to read higher than 5 ppm. It is actually able to go up beyond 50! So you got a good one there.
Yes, you have a good handle on the basics of how the CYA/FC relationship works.
As far as draining goes; please wait until you get your TF kit. The testing at pool $tores is usually wrong and CYA is almost never right. Your kit will give you a number you and we will trust.
To answer your questions:
Yes, the TF kit has the ability to read higher than 5 ppm. It is actually able to go up beyond 50! So you got a good one there.
Yes, you have a good handle on the basics of how the CYA/FC relationship works.
As far as draining goes; please wait until you get your TF kit. The testing at pool $tores is usually wrong and CYA is almost never right. Your kit will give you a number you and we will trust.
As Woody said, your CYA could be much higher. 100 is the limit of the CYA test, so at that level we are unsure if it is 100 or some number above 100.
Now, once you get your test kit and verify the CYA is 100+ (this is the test pool $tores mess up the most) I would recommend at least a 33% water exchange to get the CYA down. For vinyl lined pools leave at least one foot of water in the shallow end to keep from floating the liner and all pool owners are cautioned that in areas with a high water table lowering the water too much can “float” the pool out of the ground.
Just as an example, 3 pool $tores told me you CYA was in the 90 - 100 range and when I got my test kit the closest I could figure it was around 250.
Ok, I'll wait till I get the new test kit and have some accurate info before draining. The pool water looks great. I just got rid of a grandkids infestation so the pool was definitely stressed. I will bring the chlorine level up a bit as that would be appropriate for a generally high CYA as I have been keeping FC at 3ppm.
Oops, upside down
Oops, upside down
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We do not know why that happens LOL but it is fine! That is a pretty pool!
Kim :cat:
Kim :cat:
The sad thing is that those same industry standard chlorine ranges were printed on test kits and chlorine packages 30-40 years ago when scientific testing was already starting to show the effects of CYA on FC, to say the industry is slow to adapt to changes in chlorine recommendation is a bit of an understatement, glacial is probably a better word for it.
Yippee, got my tf100 test kit. While I was waiting I did a drain and fill and my cya test is 50-55. Having so much fun, I did it multiple times. Im following the calculator with a min of 4 and target of 6 and riding the wave of success. I was surprised my standard OTO test is usually 1.5 lower than the FAS/DPD test results. I guess that kept me out of trouble with my high CYA because my TC was higher than I thought.
Now on to my CH. Leslie's said it was 600, I did the drain and fill, my tap water CH tests at 250, but when I do the CH test with pool water it turns purple. I've done the fading end point test changes without luck either. More tests tomorrow TA for one. Thanks for everyone's encouragement! Jim
Now on to my CH. Leslie's said it was 600, I did the drain and fill, my tap water CH tests at 250, but when I do the CH test with pool water it turns purple. I've done the fading end point test changes without luck either. More tests tomorrow TA for one. Thanks for everyone's encouragement! Jim
Ok, let the fun begin. Nice work on the CYA!
On the CH, have you read post #7 on this link? Extended Test Kit Directions
On the CH, have you read post #7 on this link? Extended Test Kit Directions
Yep, that's why I know about the purple fading endpoint. I'm just glad my granddaughters aren't in charge of test kit colors. Everything would end up "tinker bell" green and I'm still not sure what that looks like. Jim