Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Which measure of CH and TA?

  1. Back To Top    #1
    tfoggo's Avatar
    Join Date
    Jul 2016
    Location
    United Kingdom
    Posts
    12

    Which measure of CH and TA?

    My photometer gives me the option of two readings when I test for CH or TA:

    CH: produces readings in CaCO3 and Ca
    TA: produces readings in CaCO3 and HCO3

    Having read around TFP a bit, I think I should be paying attention to the Ca reading for CH and the HCO3 reading for TA - am I right?!

  2. Back To Top    #2
    Mod Squad JVTrain's Avatar
    Join Date
    Feb 2014
    Location
    Central Minnesota
    Posts
    5,079

    Re: Which measure of CH and TA?

    You actually want to use the readings for CaCO3 for both TA and CH. CaCO3 is used as the equivalent for pool testing by convention.

    Is there a reason you're using a photometer versus Taylor reagents for testing?
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

  3. Back To Top    #3
    tfoggo's Avatar
    Join Date
    Jul 2016
    Location
    United Kingdom
    Posts
    12

    Re: Which measure of CH and TA?

    Quote Originally Posted by JVTrain View Post
    You actually want to use the readings for CaCO3 for both TA and CH. CaCO3 is used as the equivalent for pool testing by convention.

    Is there a reason you're using a photometer versus Taylor reagents for testing?
    Thanks JVTrain.

    I chose this photometer when I took on my first pool 4 years ago because I figured that it would provide more accurate and consistent readings than a manual kit. Also, it offers the capability to test all the elements of water balance I need with one device whereas other options seem to require buying different kits for different elements. Did I choose wrong?! Are there downsides to photometers? I don't think Taylor test kits are available in the UK, but I'm sure there will be equivalents available.

    All the best.
    40,000 ltr (10,600 US gals) in-ground, fresh water, vinyl, 'hopper style' pool. Single skimmer. Single main drain. Pentair Tagelus TA-40 sand filter (pea gravel base layer + periodic additions of DE). Sta-Rite 5P2RE-1 (1.0HP/0.75KW) pump. Calorex Pro-Pac 16Y air source heat pump. Dolphin Supreme M4 robot cleaner. Zodiac MX8 Suction Pool Cleaner. Lamotte 'FAS-DPD Commercial 7' test kit.

  4. Back To Top    #4
    Mod Squad JVTrain's Avatar
    Join Date
    Feb 2014
    Location
    Central Minnesota
    Posts
    5,079

    Re: Which measure of CH and TA?

    Photometers can work just fine, as long as they are frequently calibrated and verified for calibration. There is no substitute for reliability and accuracy for the FAS-DPD test for FC/CC. I strongly recommended having that test for maintaining your chlorine levels.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

  5. Back To Top    #5
    tfoggo's Avatar
    Join Date
    Jul 2016
    Location
    United Kingdom
    Posts
    12

    Re: Which measure of CH and TA?

    Thanks again JVTrain.

    I confess that I've only had my photometer calibrated once since I got it, so will do that more frequently. Also, I've just ordered a set of test solutions for it that will apparently tell me whether or not it needs calibration.

    Thanks for the advice!
    40,000 ltr (10,600 US gals) in-ground, fresh water, vinyl, 'hopper style' pool. Single skimmer. Single main drain. Pentair Tagelus TA-40 sand filter (pea gravel base layer + periodic additions of DE). Sta-Rite 5P2RE-1 (1.0HP/0.75KW) pump. Calorex Pro-Pac 16Y air source heat pump. Dolphin Supreme M4 robot cleaner. Zodiac MX8 Suction Pool Cleaner. Lamotte 'FAS-DPD Commercial 7' test kit.

Posting Permissions

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