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Thread: Testing for CYA - different results for different methods

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    Water_man's Avatar
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    Testing for CYA - different results for different methods

    Hi all,

    I'm in the process of opening my pool, although the current weather indicates that the swimming pool season wouldn't start until mid July

    Obviously, the first two values we check are pH and CYA.
    The pH was high so I lowered it to 7.2.

    For CYA I used the Taylor kit and the TF Test Kits. I like the TFT for CYA because it can measure lower values up to 20 while the Taylor stops at 40. Both kits were about 2-3 years old and during the off season they were kept in the fridge.
    Here are the results:
    two different dip strips - close to zero.
    pool supply store: 9
    TFT: 40
    Taylor - at 40 I could still see the black dot.
    It's hard to believe that four are wrong and only one is right.
    So I went with 9 ppm.

    I just wonder what happened to the reagent of the TFT Kit.
    This is my ticket for Heaven (when all's working..) :
    22k Gal gunite IGP, 38 SF Anthony DE filter, 1 HP Hayward Super Pump
    380k BTU Raypak Natural Gas Heater (Model RP405A) and solar cover
    8 gal Liquidator w/ 12% bleach, Dolphin Diagnostic Advantage robotic cleaner. 3800 ppm salt, 50 ppm borates.

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    Crzyfrlss1's Avatar
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    Re: Testing for CYA - different results for different method

    I'm just wondering if it's really feasible to keep a test kit in the fridge?
    Intex 15' X 48" metal frame pool
    Waterway Supreme 1hp 2 Speed pump
    Hayward X-Stream 150 Sq. Ft. Cartridge Filter
    2-2'x20' Sungrabber Solar Panels hooked up in parallel on a Goldline GL-235 controller.

    Not getting "Pool Stored" = Priceless!!!
    Thank you TFP

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    Re: Testing for CYA - different results for different method

    Doesn't Taylor recommend yearly replacements for reagents?
    16x28 Roman, 55000 litres, salt water, Zodiac Duoclear 130 (mineral cartridge removed!!!), inground, vinyl liner
    Hayward Tri-star VS900 (1.85 HP) pump, Hayward C3030 cartridge filter
    Nine Techno Solis 4x10 solar panels, Jandy LX 250 natural gas heater
    Jandy Aqualink PDA with Sub Panel Power Centre

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    Water_man's Avatar
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    Re: Testing for CYA - different results for different method

    Quote Originally Posted by rcy
    Doesn't Taylor recommend yearly replacements for reagents?
    Certainly. What's wrong with having more sales? Most chemical reagents are stable , especialy in low temp.
    This is my ticket for Heaven (when all's working..) :
    22k Gal gunite IGP, 38 SF Anthony DE filter, 1 HP Hayward Super Pump
    380k BTU Raypak Natural Gas Heater (Model RP405A) and solar cover
    8 gal Liquidator w/ 12% bleach, Dolphin Diagnostic Advantage robotic cleaner. 3800 ppm salt, 50 ppm borates.

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    Re: Testing for CYA - different results for different method

    Quote Originally Posted by Water_man
    I like the TFT for CYA because it can measure lower values up to 20 while the Taylor stops at 40.
    :
    TFT: 40
    Taylor - at 40 I could still see the black dot.
    :
    The Taylor kit should go down to 30 ppm, not 40 ppm (see top of vial in the photo at the bottom of this link). Was the water even cloudy when using the Taylor reagent? I have both the TF-100 and K-2006 kits and have always found them to be consistent.
    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
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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    Water_man's Avatar
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    Re: Testing for CYA - different results for different method

    Quote Originally Posted by chem geek
    The Taylor kit should go down to 30 ppm, not 40 ppm (see top of vial in the photo at the bottom of this link). Was the water even cloudy when using the Taylor reagent?
    You're right. I didn't read the number well - I thought that all the way to the top was forty. The water was indeed cloudy
    This is my ticket for Heaven (when all's working..) :
    22k Gal gunite IGP, 38 SF Anthony DE filter, 1 HP Hayward Super Pump
    380k BTU Raypak Natural Gas Heater (Model RP405A) and solar cover
    8 gal Liquidator w/ 12% bleach, Dolphin Diagnostic Advantage robotic cleaner. 3800 ppm salt, 50 ppm borates.

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    Re: Testing for CYA - different results for different method

    Quote Originally Posted by Water_man
    I'm in the process of opening my pool, although the current weather indicates that the swimming pool season wouldn't start until mid July


    I hear you on that!! Just got mine all converted over from Baqa-poo to the BBB method and it's been mostly lousy days since. I was lucky enough to be home early this week and got two days in.

    Let's hope for some improvement up here in MA!
    13500 gal 15x30 oval AG, Hayward DE filter

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    frogabog's Avatar
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    Re: Testing for CYA - different results for different method

    The CYA reagent I'm using is from an out of business company called Master Tech (I think) which is a full old school color comparitor kit that tests to 10ppm FC and TC. Dad handed me down this massive kit so I may as well use up what still works, right? There are two full bottles of the CYA reagent (it's like a goldmine... they are 2oz bottles), which have to be at least 10, if not 15 years old and if they work, I figure I'll use them up and buy more later.

    So I got a new HTH 6-way kit, and compared. Same result. Spa/pool store guy said it should be fine when I inquired (shrugged it off as if it doesn't really expire). I don't know how much he knows for sure but he didn't try to sell me new CYA reagent, so he gets a point for that.

    It seems to work fine and I know it's ancient. YMMV of course. I can guarantee it was not stored properly, however our climate is fairly mild (if you don't consider rain an extreme weather condition).

    I'd go with the taylor and TFT numbers and call it 40-45, 9 seems kinda low. How much water did you replace since closing last year? What was CYA then? Check the calculator but I bet it won't change minimum and target if it's 40 or 45 and if you dose to get from 9 to 40 and you're really at 40, then you'll be at 70.

    Happened to me this year. Overdose... (only by 10ppm tho). I didn't loose as much as I thought by draining for winter and the gallons of rain that fell. Those dip strips never register CYA unless it's 40 or above anyway. I only saw the slightest change after the overdose on the dip strip test (40ppm). I didn't trust the old CYA yet and used a couple dips when I opened the pool. They fooled me into thinking it was 10 or less because it was soooooo light. I then added 20ppm CYA and overshot it by 10ppm.

    The weather here sucks too. 20-30 CYA works for us, we lack all that sun everyone else has to deal with. Maybe when the kids get back from camp in a week the sun will be out. The forecast is... bleak.
    Where kids swim in 54 degree water, turn blue, and giggle happily cuz they got a POOL!
    Year 3 BBB -15' x 48" Intex Metal Frame - Was using (2) 1000gph Intex cartridge filters (see Full time pumping Intex). 2012, converted to 1600gph and sand filter+SWG = Sand filter love affair!
    Don't waste time and energy looking for a better value on test kits, the TF100 is the best deal around. I did the looking and spent the extra money, but you don't have to make the same mistake. Just go here: TFTestkits. I use Pool Calculator for min/max, and shocking chlorine levels.

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