- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
Local area pool store water testing descrepancies
- Thread starter mijmic
- Start date
A little concerned about your FC tests. You recorded a 22 and then a 30? I never noticed that you have added liquid chorine. We might need to confirm your test process
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You might find this link interesting regarding your OTO chlorine test results Extended OTO color comparator?
Having a speed stir helps with the accuracy when you have high levels of FC and helps with the TA and CH testing, too. The FAS-DPD Chlorine (powdered based FC) sample will turn pink if you let it sit around or take too long to perform the test. Make sure that you read the extended testing directions here: Pool School - Extended Test Kit Directions
I took a water sample last night around 11 p.m., some half hour after turning off the SWG. I recorded an FC reading of approx. 19 ppm.
This a.m. at approx. 8:45 a.m., I gathered another sample to complete the OCLT. I recorded an FC reading of approx. 18 ppm...so I believe at a 1 ppm difference, this is okay/acceptable. I also ran a CC, CH & TA test again at the same time:
CC = 0
CH = 375 ppm
TA - 90 ppm
Per the option details when placing the TF-100 order, I did purchase the optional $35.00 speed stir along with the salt test strips. In my testing conducted yesterday & this morning, I didn't use the speed stir, and, actually wondered some that I should've just placed that additional $35.00 towards additional chemicals. So, why does the speed stir provide better accuracy vs. the quick swirling method with the two vials included in the TF-100? I noticed that the vial that comes with the Taylor speed stir is longer and harder to read as the ml readings/levels aren't in black, but clear...making it harder to read. Can I use the vials included with the kit with the speed stir, or do I have to use the dedicated vial that came with it?
Oh, and why when doing the TA test does it call for wiping the R-0009 bottle tip after each drop? Just curious to its significance as with the other solution bottles, the written instructions don't call for this.
Thanks!
This a.m. at approx. 8:45 a.m., I gathered another sample to complete the OCLT. I recorded an FC reading of approx. 18 ppm...so I believe at a 1 ppm difference, this is okay/acceptable. I also ran a CC, CH & TA test again at the same time:
CC = 0
CH = 375 ppm
TA - 90 ppm
Per the option details when placing the TF-100 order, I did purchase the optional $35.00 speed stir along with the salt test strips. In my testing conducted yesterday & this morning, I didn't use the speed stir, and, actually wondered some that I should've just placed that additional $35.00 towards additional chemicals. So, why does the speed stir provide better accuracy vs. the quick swirling method with the two vials included in the TF-100? I noticed that the vial that comes with the Taylor speed stir is longer and harder to read as the ml readings/levels aren't in black, but clear...making it harder to read. Can I use the vials included with the kit with the speed stir, or do I have to use the dedicated vial that came with it?
Oh, and why when doing the TA test does it call for wiping the R-0009 bottle tip after each drop? Just curious to its significance as with the other solution bottles, the written instructions don't call for this.
Thanks!
You can use any of the vials. And once you try the speed stir you will realize why you invested in it...trust me
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You can use any vial you want with the speed stir. Why do you think your FC values are approximate? You need precise values especially when doing an OCLT.
Okay...I'll give it a try next time.
In regards to your post above (#64) about my 22 and 30 ppm readings...I was just experimenting with the mentioned palely pink vs. 'completely' clear as those were my first tests I've done using the kit.
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Got it...thanks!
The approximates is because I just rounded up. 37 drops last night at 11-ish. So, X 0.5 = 18.5 ppm or 19. 8:45 this morning I did the same thing...35 drops, so 17.5 ppm rounded up to 18. So, no rounding up?
You passed the OCLT! Congratulations!
No, never round the FC or CC values.
Is there any cloudiness or haziness to the water? Can you see the screw heads on the main drain or tell if a quarter is heads or tails on the deep end?
No, never round the FC or CC values.
Is there any cloudiness or haziness to the water? Can you see the screw heads on the main drain or tell if a quarter is heads or tails on the deep end?
Okay...thanks!
No cloudiness, etc. the water is very clear. I can see the screw heads on the bottom drains, even with the constant minor ripples in the water from the spa spillover. Our pool is 4 to 6 to 4...drains are in 6' of water.
My biggest problem to date (prior to this apparent cc problem) in the two years since the pool has been completed has been trying to keep the PH in check. My readings more time than not hover in the 7.8-8.0 range...even when dumping a gallon of MA in the water on almost a weekly basis. I learned here though in the last week or so, that aeration is a contributing factor to PH rise, my POS PB never mentioned anything about this, nor any of the store testing places I have been to. My spa spillover is pretty big, since I have a pretty good size spa...about 3' spillover. By design, this runs/circulates all the time when pump is on in pool mode.
I tweaked down my SWG from 75 to 55% for the time being until FC gets in the 3 to 5 range per 70 CYA w/SWG. Is that okay, or should I bump up/tweak down?
No cloudiness, etc. the water is very clear. I can see the screw heads on the bottom drains, even with the constant minor ripples in the water from the spa spillover. Our pool is 4 to 6 to 4...drains are in 6' of water.
My biggest problem to date (prior to this apparent cc problem) in the two years since the pool has been completed has been trying to keep the PH in check. My readings more time than not hover in the 7.8-8.0 range...even when dumping a gallon of MA in the water on almost a weekly basis. I learned here though in the last week or so, that aeration is a contributing factor to PH rise, my POS PB never mentioned anything about this, nor any of the store testing places I have been to. My spa spillover is pretty big, since I have a pretty good size spa...about 3' spillover. By design, this runs/circulates all the time when pump is on in pool mode.
I tweaked down my SWG from 75 to 55% for the time being until FC gets in the 3 to 5 range per 70 CYA w/SWG. Is that okay, or should I bump up/tweak down?
You can turn off your SWG and let the FC drift down. You want to have a target FC of 5 and you don't want your FC to get to 3 as that too close to FC of 2 which will allow algae to grow. I try to keep my FC a little above target so that it can handle my lab getting into out of the pool 100s of times a day bringing in his muddy paws and dirty toys. So, you might want to kick the SWG back on when you get to 6 or 7 so have a buffer while you determine your run time and %.
Most of us keep our run time and % at the same level throughout the week and dump in bleach if we have a large bather load like on the weekends as SWG are good at maintaining, but bad at increasing FC.
You'll need to get a handle on your TA as higher TA makes PH rise faster. Having a SWG and a spill over will also increase your PH faster. Some of us keep our TAs around 50, but you'll have to figure out which TA level will help to keep your PH from rising too fast. Read this article about lower TA: Pool School - Lower Total Alkalinity
Most of us keep our run time and % at the same level throughout the week and dump in bleach if we have a large bather load like on the weekends as SWG are good at maintaining, but bad at increasing FC.
You'll need to get a handle on your TA as higher TA makes PH rise faster. Having a SWG and a spill over will also increase your PH faster. Some of us keep our TAs around 50, but you'll have to figure out which TA level will help to keep your PH from rising too fast. Read this article about lower TA: Pool School - Lower Total Alkalinity
- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
+1 to a minimum of 4 ppm FC for CYA at 70 ppm.
I know the chart says 3, but considering the likelihood of error in the CYA test and that the actual calculation wold be 3.2 anyway (using minimum of 4.5% of CYA from Chem Geek's footnote), 3.5 or 4 is a safer minimum.
I know the chart says 3, but considering the likelihood of error in the CYA test and that the actual calculation wold be 3.2 anyway (using minimum of 4.5% of CYA from Chem Geek's footnote), 3.5 or 4 is a safer minimum.
The wiping of the tip for that test is to discharge the static electricity. It helps keep the drops consistent.
Okay. Thanks again for all your help & advice, it's very much appreciated.
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The wiping of the tip for that test is to discharge the static electricity. It helps keep the drops consistent.
Thanks for your response...I figured there had to be a reason that made some sense.
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Okay, thanks! I'll keep in the safe zone...or at least try.
I have a general question. Is there a standard type FC loss considered normal/day during the summer months? Or, are there too many variables like amount of direct sunlight the pool gets, CYA levels, temperature of the water, swimmer load, etc.
Our pool during the summer months sits in direct sunlight from approx. 9 a.m. to 4 p.m., however, it typically doesn't get heavy swimmer activity. SE Charlotte's daily temps are typically in the low to mid 90's during June, July & August, we've had over 70 90 degree days so far this summer. A few weeks back our pool water temp was 96 degrees for a solid 3 weeks dropping no lower than 92. We have recently had a little bit cooler weather with more clouds than sun, thus, the pool water is currently at 89 degrees, which is the lowest it has been since early June.
I'm trying to get a general idea of typically (when Chlorine is in the desired target range) how much FC I should be adding per day, per week, etc. considering I have a SWG and it has been mentioned here that SWG's are good for maintaining levels of FC, but not adding.
Thanks!
Our pool during the summer months sits in direct sunlight from approx. 9 a.m. to 4 p.m., however, it typically doesn't get heavy swimmer activity. SE Charlotte's daily temps are typically in the low to mid 90's during June, July & August, we've had over 70 90 degree days so far this summer. A few weeks back our pool water temp was 96 degrees for a solid 3 weeks dropping no lower than 92. We have recently had a little bit cooler weather with more clouds than sun, thus, the pool water is currently at 89 degrees, which is the lowest it has been since early June.
I'm trying to get a general idea of typically (when Chlorine is in the desired target range) how much FC I should be adding per day, per week, etc. considering I have a SWG and it has been mentioned here that SWG's are good for maintaining levels of FC, but not adding.
Thanks!
This great question is why I suggest keeping a log of all of your tests results. I have a small notebook I keep mine in. After a while you will notice a pattern. I even note "weather"-cloudy, rainy, windy, VERY hot, etc.
"Normal" daily loss of FC is 2-5 ppm. Like you noted it depends. The log will help you really learn your pool and it's needs.
"Normal" daily loss of FC is 2-5 ppm. Like you noted it depends. The log will help you really learn your pool and it's needs.
- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
Yeh, FC per day is a wide range for the reasons you mentioned along with incoming contamination (leaves, bugs, etc.) or use of a cover. I've heard anything from 0.5 ppm FC per day up to around 4.0, but most people say 2 to 3, with 4 reserved for the hotter days with bather load.
Holydoc
Gold Supporter
- Jul 17, 2016
- 515
- Pool Size
- 17500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
This great question is why I suggest keeping a log of all of your tests results. I have a small notebook I keep mine in. After a while you will notice a pattern. I even note "weather"-cloudy, rainy, windy, VERY hot, etc.
"Normal" daily loss of FC is 2-5 ppm. Like you noted it depends. The log will help you really learn your pool and it's needs.
Kim, as always, is right on target. I have been keeping a log of my test results (mostly to get an idea of how much the pool is costing me so I can budget it), and you will definitely see a pattern. I could tell you what the weather was like outside just by how much chlorine I had to add for that day. A bright sunny 96 degree day would warrant a loss of FC of 3 to 3.5. An overcast day is typically a loss of 2 to 2.5. As the pool water cools down, as it has this last week, I am typically getting a loss of 2ppm/day. Heck I even nearly had a panic attack one day when I tested and found I had loss 5ppm instead of the normal 3ppm. Then I looked at my test log and saw that I had dumped some old algaecide that I had left from when I was being Pool Stored into the pool the night before to just get rid of it. That is when I discovered that Chlorine will also react with algaecides causing you to lose an excess.
So long story not shortened
, it is a little bit different from pool to pool. But your pool will have its own unique pattern that will help you to predict how to treat it. Heck I was able to go on a TDY and just averaged the amount of chlorine per day I would need and told my wife to just add half a gallon of chlorine a day. I came home from TDY to have a perfect pool waiting on me. Keep a log. Learn your pool's needs.Test when the pump has been running for a bit. More accurate sample if the water is circulated.