Test Questions

Flynn713

Member
Aug 25, 2014
22
Oakville, Ontario, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Hi everyone,
I'm using the Taylor 2006 FAS-DPD test kit.
1. For my first tests on Monday I used the 25 ml sample line and had to add 37 drops of R-0871...so my FC is around 7.4? Seems too high, and I'm wondering what I did wrong?
2. No combined chlorine was found, that's good, right?
3. pH was 7.2
4. Alkalinity was 80 ppm.
5. Cyanuric Acid was 38 ppm.

On Wednesday, I tested again with a 10 ml sample and got a FC reading of 4.5 ppm. Only a slight pink colour on the combined chlorine test, 1 drop to make it colourless.
I realized that I my stabilized pucks had just run out, topped them up this morning. pH is 7.4.
Everything seemed to be in order except my first test for FC. Any idea why it was so high/off? Thanks in advance, Flynn
 

Texas Splash

Mod Squad
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Jun 22, 2014
33,893
Texas, San Antonio/Marion, South-Central Area
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Flynn, you may have already seen this page: Extended Test Kit Directions, but I wanted you to have it just in case. I always use the 10ml when I test, and just to confirm ... make sure after you add the power and swirl, that once you get your final drop count of R-0871, that you divide the total number in half (x .5). Example: It took 34 drops to change from pink to clear, then your FC = 17. I wasn't sure you did it that way from your explanation above. Just wanted to make sure. :)
 

lefty51

Platinum Supporter
Flynn, you may have already seen this page: Extended Test Kit Directions, but I wanted you to have it just in case. I always use the 10ml when I test, and just to confirm ... make sure after you add the power and swirl, that once you get your final drop count of R-0871, that you divide the total number in half (x .5). Example: It took 34 drops to change from pink to clear, then your FC = 17. I wasn't sure you did it that way from your explanation above. Just wanted to make sure. :)

Good point TS, that would explain the difference. Also I always like to add that after you test for FC, if you let sample set a bit, it starts to turn back pink. So don't dally before testing for CC. I sometimes have a slight shade of pink that one drop clears, so I don't worry about it

- - - Updated - - -
 

Flynn713

Member
Aug 25, 2014
22
Oakville, Ontario, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Flynn, you may have already seen this page: Extended Test Kit Directions, but I wanted you to have it just in case. I always use the 10ml when I test, and just to confirm ... make sure after you add the power and swirl, that once you get your final drop count of R-0871, that you divide the total number in half (x .5). Example: It took 34 drops to change from pink to clear, then your FC = 17. I wasn't sure you did it that way from your explanation above. Just wanted to make sure. :)

For the first test I used the 25 ml test line and had to add 37 drops, so 37 x .2 = 7.4, right? But maybe I took too long between testing FC and CC? I tested around 2 pm in the afternoon.

- - - Updated - - -

Hi Flynn, well everything else looks great. Did you by any chance check the chlorine at night or first thing in the morning and second test after the sun had been on pool all day ? That could explain FC drop.

Remember the pucks will add CYA and raise PH, so use accordingly:D

Hi Lefty51, thanks for the response. I have started to read the forums, but I haven't completed them all yet...your comment about the pucks above, is there something I'm missing, I thought I had to have some CYA going into my pool from my chlorinator?
 

duraleigh

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In The Industry
Apr 1, 2007
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Sebring, Florida
This may be my dumbest day ever but I don't understand. Of course you will get different FC readings on different days......FC is constantly being consumed. I must be overlooking something?

PS - FC of 7.4 is not necessarily high.....compared to what?
 

Flynn713

Member
Aug 25, 2014
22
Oakville, Ontario, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
This may be my dumbest day ever but I don't understand. Of course you will get different FC readings on different days......FC is constantly being consumed. I must be overlooking something?

PS - FC of 7.4 is not necessarily high.....compared to what?

Thanks Duraleigh, I thought FC of 7.4 sounded high because I've never had a reading from a pool store that was over 4.5...so I thought maybe I did the test wrong. Maybe I took too long adding the drops?
 

Texas Splash

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Jun 22, 2014
33,893
Texas, San Antonio/Marion, South-Central Area
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Hence why we try to remind folks the importance of owning their own test kit like you - to ensure your FC is in concert with your current CYA. That relationship is not emphasized at most pool stores. As long as your FC meets-up with your CYA per the Pool School - Chlorine / CYA Chart. you are in good shape. Always try to stay at your target, anything below as you can get into (algae) trouble. Have a great day.
 

Flynn713

Member
Aug 25, 2014
22
Oakville, Ontario, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Ok TS, thank you. It seems from the chart on CYA & FC levels that if my CYA is around 40, then my minimum FC level is 3 and my target is 5. I'll try to keep those levels as I test daily over the next week or so.
 
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