I have been using the Lamotte Color Q pro since the pool opened in early June. It always gives me a reading for FC in the ballpark want: 1.5 to 2.0 ppm. I also have a Taylor K-2005 kit that uses the pink water color comparison test which I do not use because of the inaccuracy. So a few weeks ago I bought the R-0871 (FAS-DPD Titrating reagent and the R-0870 the powder that turns the water sample pink. I always get a much higher result from the FAS-DPD test than with the Color Q pro. Today the Color Q gave me an FC result of 1.87 ppm. I immediately did the test with the Taylor as follows: fill the large tube up to 25 ml level, cap and mix thoroughly. Then add two scoops powder with the tiny spoon, mix thoroughly and it turns pink. Then added R-0871 titrating reagent to the tube dropwise while counting the drops until the water in the tube turns from pink to clear. I was careful to mix up the water in the tube thoroughly as I went along. Today, I added 19 drops. This is multiplied by 0.2 and the result is 3.8 ppm free chlorine. Does anyone have an opinion as to which one is correct? Am I doing the Taylor FAS-DPD test correctly? The procedure I followed is taken directly from the Taylor website.
I need help determining the correct FC level.
- Thread starter Bwdonohues58
- Start date
You say you filled the tube to 25 mL, capped and stirred. Stirred what?
I use 10 mL sample because 0.5 accuracy is plenty. 10 mL pool water, then add the Speed Stir bar. Turn on Speed Stir. Add one scoop powder. Count the drops and divide by two.
As for which is more accurate, the drop kit or the meter, the answer is the drop kit so long as you followed proper procedure. Make sure you hold the drop bottle vertically and squeeze slowly so gravity takes the drops.
I use 10 mL sample because 0.5 accuracy is plenty. 10 mL pool water, then add the Speed Stir bar. Turn on Speed Stir. Add one scoop powder. Count the drops and divide by two.
As for which is more accurate, the drop kit or the meter, the answer is the drop kit so long as you followed proper procedure. Make sure you hold the drop bottle vertically and squeeze slowly so gravity takes the drops.
- Jun 22, 2014
- 47,896
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
I agree. ^^ 
I'd trust the FAS-DPD every time. I also use the 10 ML sample size as it's plenty accurate and saves a bit of reagent.
www.troublefreepool.com
I'd trust the FAS-DPD every time. I also use the 10 ML sample size as it's plenty accurate and saves a bit of reagent.
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Thanks. I am going to shelve the meter as I think I might have a lemon.
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