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Thread: This normal for the FAS-DPD test tube?

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    This normal for the FAS-DPD test tube?

    Mine came in the mail today and I don't know if it shows but the lines are crooked. Won't this mess up my water levels. It's harder to see in the picture, but pretty noticeable in person:

    new house: TBDK gal IG plaster pool, filter Titan CM DE filter 36 sq ft , 1.5 HP Pump; Polaris 380

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    Re: This normal for the FAS-DPD test tube?

    Hard to tell in your picture. The main thing you are measuring is your drops anyway. The lines are only to start your water sample with your 10ml. Can you put 10ml in your other cylinder then pour it here and see where it correlates with the line for 10? then you'll know the line and you can test with your drops. The line has nothing to do with your results..only your starting water sample...if that makes sense.
    You can also measure 10ml in a medicine cup..they go to 30ml... for a reference point.
    Location: East TN
    ? 15x30 Lomart Above ground

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    Re: This normal for the FAS-DPD test tube?

    My cylinders are not right I have to measure my water in another way, I use a syringe or a child's medicine measurer. I like the test kit very disappointed that I have to measure with syringe first. Not having the right amount of water in the sample alters what your ppm is, at least that is my opinion others say it does not matter.

    Like all advice you have to take what is good and discard the rest. So far the good out weighs the bad on this forum.
    18,500 gallon, 16' x 38' freeform ig plaster w/ 7 ft spill over spa
    Pentair C&C+ 420 cart, Inteliflo 4 x 160 pump - new plaster on 5/5/09

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    Re: This normal for the FAS-DPD test tube?

    carrolton and camelai,

    Please PM me and let me know who you are and we'll ship new cylinders to you.

    Fixing issues like that is very easy to do.........just let us know.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: This normal for the FAS-DPD test tube?

    Quote Originally Posted by duraleigh
    carrolton and camelai,

    Please PM me and let me know who you are and we'll ship new cylinders to you.

    Fixing issues like that is very easy to do.........just let us know.
    Will do. That was my next step this morning. PM Sent
    new house: TBDK gal IG plaster pool, filter Titan CM DE filter 36 sq ft , 1.5 HP Pump; Polaris 380

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    Re: This normal for the FAS-DPD test tube?

    Quote Originally Posted by camelai
    My cylinders are not right I have to measure my water in another way, I use a syringe or a child's medicine measurer. I like the test kit very disappointed that I have to measure with syringe first. Not having the right amount of water in the sample alters what your ppm is, at least that is my opinion others say it does not matter.

    Like all advice you have to take what is good and discard the rest. So far the good out weighs the bad on this forum.
    It should be clear that the size of the initial sample affects the ppm result. A 10 ml sample results in a .5ppm value per drop. If you use a 25ml sample the value is 0.2 ppm per drop. (This is the way the Taylor K-2006 is set up, using the same reagents.) A larger than nominal initial sample will therefore result in a lower FC value per drop than nominal, thus requiring more drops and yielding a higher than accurate FC value.

    What does not matter is the precise amount of powder added to the measured initial sample volume, so long as the minimum concentration required is achieved.
    Current: 28,000G 18'x36' I/G AnthonySylvan Plaster; Waterway 60 sq.ft. DE Filter; 1.0hp x 1.65 SF Two-Speed (B2982) WhisperFlo; 2004-Present
    Previous: 40,000G 20'x40' I/G Koven unlined WWII salvage 5/8" marine steel; Lomart Stainless Sand Filter; 3/4hp Hayward SuperPump; 1946-2003 (managed by me from about 1964)
    Ancient Taylor K-2000, upgraded with Taylor CH, TA, and FAS-DPD, and TFT CYA tests.

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    Re: This normal for the FAS-DPD test tube?

    I noticed last year that when I measured 10ml of water into the vials I received, the water level was at 12ml. I posted and was told it won't effect the result. I don't agree, but I am not an expert. We are striving to obtain accurate test results and the accuracy would be off with a different amount of water. I have some old vials from a previous test kit that I use since they do measure exactly 10ml.

    Dave did send me some new vials over the winter, but since I still haven't opened my pool I had not checked to see if they were correct. Unfortunately, I just checked them and it seems I now have the opposite problem. When I measure 10ml of water it shows only 8ml of water in the new vials.

    I suppose it is possible that my medicine dropper (marked in ml for dosing children) could be marked incorrectly, but since I can use it and get the correct amount with the vials from the previous test kit I tend to think it is accurate.
    24ft AGP 52in deep ~13,500 gal
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    Re: This normal for the FAS-DPD test tube?

    An error of 2 ml out of 10 ml would be a 20% error in your FC reading. It is not true that it will not affect the result.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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