Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Two Store test measures chlorine but 2 brands of home test strips do not. What?

  1. Back To Top    #1

    Join Date
    Jun 2014
    Location
    Erie pa
    Posts
    2

    Two Store test measures chlorine but 2 brands of home test strips do not. What?

    I went to a local pool store to have my water tested. Their computerized test measures all chemicals in balance. Free chlorine 1.65. Total chlorine 1.65. Ph 7.2. Alk 109. Cyn acid 75. Pool temp 80. Live in PA. The pool store test involved measuring the water in several different vials and putting the vials in a digital reader attached to the computer. Water is crystal clear. Sand filter recently back washed. Sounds good, right?

    Problem: htp brand and aqua check brand pool strips register chlorine level as zero. The pool store owner used both of these test strips at my suggestion in the water sample I brought and got the same result I got at home...chlorine reads zero on these strips. So Why do these strips, which for the past 5 years used to measure all chemicals correctly for me, they do not measure chlorine?

    We even checked his computer test and compared it to a test involving testing the water with drops and comparing the water in a rectangular vial that had color test strip on the side of the vial and even this test showed the chlorine was fine.

    So what do I do now?

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Two Store test measures chlorine but 2 brands of home test strips do not. What?

    Welcome to TFP!

    Dependable accurate water testing is the foundation of pool care. None of those test results are what we consider reliable. Pool store testing is frequently wildly wrong, with the computerized systems usually being the furthest off. Problems with pool store testing are far more common than you might imagine. And you should never trust test strips.

    Worse, what you call "in balance" is not even similar to what we call in balance. The FC level you report from the pool store is way way too low for a CYA of 75.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3

    Join Date
    Jun 2014
    Location
    Erie pa
    Posts
    2

    Re: Two Store test measures chlorine but 2 brands of home test strips do not. What?

    So what do I do?

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Two Store test measures chlorine but 2 brands of home test strips do not. What?

    Your best long term option is to get your own top quality test kit. A good kit, like the ones we recommend (see the Pool Chemistry section of Pool School), will give you better results than most pool stores right from the first day.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. Back To Top    #5
    Isaac-1's Avatar
    Join Date
    May 2010
    Location
    SW Louisiana
    Posts
    6,711

    Re: Two Store test measures chlorine but 2 brands of home test strips do not. What?

    First let me say welcome, second to follow up on what Jason said, many pool store computerized testers are designed to LOOK fancy and technical to give the impression that you should trust them, many of these systems are not so good in reality, although I will admit some may be getting better. However one of the key problems with many of these computerized tester is the simple fact they are out of calibration, as regular calibration to known good reference samples is an important step in most computerized testers. It is hard to say more without knowing the exact type of test setup this store has, however our suggestion is always going to be the same, ditch the test strips and buy one of the suggested drop based test kits in the pool school link in the upper right (I use the TF-100, see my signature for link as it provides the best bang for the buck). While you are reading pool school I would also suggest you read some of the other pool care chemistry articles like: http://www.troublefreepool.com/conte...ater-chemistry
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
    ~Remember TFP counts on your donations to keep this site ad free~

  6. Back To Top    #6
    Mod Squad YippeeSkippy's Avatar
    Join Date
    Jan 2012
    Location
    'burbs of Augusta, Georgia
    Posts
    6,459

    Re: Two Store test measures chlorine but 2 brands of home test strips do not. What?

    Just as an example of dubious pool store testing- Yesterday I needed a small part for my pool. Lately, when I have to go to a pool store for something I've been taking water in for the free testing. Just for the fun of it, to see what they say, y'know?
    I tested my water and my CYA is 40 (I've been raising it up again slowly since Skippy accidentally drained a mess of water last month, oy!) and pool store #1 said my CYA was 27, and pool store #2 said 60.
    If that doesn't convince you that pool store testing is questionable at best nothing will! (oh yeah, pool store #1 happily informed me my phosphates were 250 and for $50 I could buy a bottle of magic phospate killer and all would be well with the world....LOL)
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •