cfherrman
TFP Guide
Your fine.
I'd be content with thinking the extra fc is being lost to bugs and dirt.
I'd be content with thinking the extra fc is being lost to bugs and dirt.
TF-100 and the CYA test
- Thread starter napkin41
- Start date
- Jun 22, 2017
- 859
- Pool Size
- 35000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45
No FC lost overnight, almost guaranteed no algae. You could bump your CYA up another 10 to help fight off the FC lost during the day, especially as summer comes around and the high heat of Texas Summer starts to take its toll.
The CYA test is quite subjective, it's variable with temperature and lighting and the operators visual acuity. If you're in doubt, I'm sure Taylors do a CYA standard solution that you can test first so you can see what it really should look like under the lighting conditions you have. It does take time and care to get it right and that is what is generally lacking in pool shop analysis. There are some photometers around that are badly designed and subject to stray light that can give poor readings, particularly outdoors in full sun, but generally well designed photometers give decent results for this test if they're used correctly. The problem is that they often aren't used correctly. One new product on the market that is being taken up by quite a few pool shops is the Waterlink Spin photometer. This instrument only requires the operator to inject 3 mL of sample into the test disc, beyond that point, mixing, lighting, development time for the reagents and the vagaries of the human eye are all operator independent. My local pool shop uses one of these and the CYA results have been accurate and consistent with changes in pool volume due to rain events and losses due to filter cleaning. Unfortunately the Taylors kits and the TF-100 kit aren't readily available in Oz and the only comparable kit here has been having issues with the CYA reagents and standards, so the pool shop is my only easy source for monitoring it. Using that particular unit it's pretty hard for them to get it wrong.
It's not perfect, I monitor pH with a pH meter, and as I am a chemist it's in my work test kit, it's a professional quality meter and kept calibrated regularly. The Waterlink test has consistently given pH results that have been 0.3 pH units higher than the meter. The TA results have been a bit lower than my titrations. Hardness has been pretty close and if I put 30 ppm of hardness in, I get that showing on the result pretty much exactly. FC and CC have been almost exactly what I get in the DPD-FAS test.
It's not perfect, I monitor pH with a pH meter, and as I am a chemist it's in my work test kit, it's a professional quality meter and kept calibrated regularly. The Waterlink test has consistently given pH results that have been 0.3 pH units higher than the meter. The TA results have been a bit lower than my titrations. Hardness has been pretty close and if I put 30 ppm of hardness in, I get that showing on the result pretty much exactly. FC and CC have been almost exactly what I get in the DPD-FAS test.
Thanks all,
I know bleach is the recommended chlorine agent, but it almost sounds like if I want to bring up CYA gradually before summer, I can save some bleach and put some tabs in my chlorinator. The pool store suckered me into a huge bucket of them before I saw the TFP light. I might as well use them with a purpose.
And thanks AusJohn, that's actually not a bad idea. I think I'll look into a standard solution for CYA to test my abilities to conduct that test! I am feeling a bit better about it, but it would be good to see how I score on that test.
Also, as I'm perfecting my chlorine routine, it appears I'm losing only about 2ppm or less a day. I think I'm in a good spot!
I know bleach is the recommended chlorine agent, but it almost sounds like if I want to bring up CYA gradually before summer, I can save some bleach and put some tabs in my chlorinator. The pool store suckered me into a huge bucket of them before I saw the TFP light. I might as well use them with a purpose.
And thanks AusJohn, that's actually not a bad idea. I think I'll look into a standard solution for CYA to test my abilities to conduct that test! I am feeling a bit better about it, but it would be good to see how I score on that test.
Also, as I'm perfecting my chlorine routine, it appears I'm losing only about 2ppm or less a day. I think I'm in a good spot!
- Jun 22, 2014
- 47,798
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
See, now THAT's what we're talking about. By testing your own water and understanding how FC and CYA go together, you CAN use tabs when you know (based on YOUR OWN testing) that the CYA is low. TFP doesn't mean never use tabs, only to use them sparingly and when you know your CYA can afford to go up. For me personally, my pool with full TX sun and water temps that spike into the lower 90s, I keep my CYA at a minimum of 60 in Jun-Sep. The other months I can let it fall to around 50 or so. In the winter when water is chilly I can really let it drop all the way down to 30-ish if I want. Your CYA may vary based on exposed sunlight or other factors, but you get the idea. Losing about 2ppm per day is very nice.
- Jun 22, 2017
- 859
- Pool Size
- 35000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45
Use PoolMath to figure out how much a single puck will effect your CYA, and you'll know how many to add then. Just please don't put it in you skimmer, that highly chlorinated and I think more acidic water isn't good for your equipment until it's diluted in all your pool water.
I used a puck last year while out of town and using PoolMath, my CYA raised exactly as much as I expected.
I used a puck last year while out of town and using PoolMath, my CYA raised exactly as much as I expected.
It's all thanks to you guys!
My PB saw fit to put a chlorinating tower downstream of my pump discharge. I think that's actually quite handy!
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