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

Thread: True Total Alkalinity Reading?

  1. Back To Top    #1

    Join Date
    Sep 2014
    Location
    San Ramon, California
    Posts
    65

    True Total Alkalinity Reading?

    Having read about this "True Total Alkalinity Reading" value and it's formula -> TA - (CYA/3), should I consider it with my water tests?

    In the Pool School Recommended levels for Plaster (with Bleach), TA should be 70-90+ ppm. But if I pay attention to this "True Total Alkalinity" formula, and if my CYA is about 30 ppm I end with some value that is almost always less from just reading the TA results from the TF-100 test kit.


    For example:

    From TF-100 test kit reading: TA = 100 ppm

    From "True Total Alkalinity" formula -> TA - (CYA/3):

    > = 100 - (30/3)
    > = 90 ppm

    So, is my TF-100 test kit's TA reading of 100 ppm good enough because if plug it into "True Total Alkalinity" formula it equals to 90 ppm? Or should I discard this "True Total Alkalinity" formula and only pay attention to my TF-100 test kits, TA reading alone thus my TA still needs to be dropped by 10 ppm?
    14,000 gals; IG gunite - Wet Edge Primera Stone finish; Sta-Rite/Pentair Intelliflo variable speed; Sta-Rite/Pentair system3 S7M400 cartrige; Sta-Rite Max-E-Therm 400 heater; (Pentair Rainbow 320 Chlorinator- for vacation use only); built-in automatic pool cover; Trident II UV system (on recall not currently used); built 10/31/2012; TFT-100; MX8 cleaner

  2. Back To Top    #2
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: True Total Alkalinity Reading?

    Who says your alkalinity needs to be reduced by 10?

    If you go to poolmath and go to the last row where it says Suggested Goal Levels and you choose trichlor as your chlorine source (you DO list a Rainbow 320 Chlorinator, after all) recommended TA is 100-120+

    If you're using bleach, then TA suggestion is 70-90+ . You're at 90+ already. You're fine.

    Poolmath takes various forms of alkalinity into account in its calculations. See True Alkalinity Readings or try the search box for more.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  3. Back To Top    #3


    TFP Guide

    cowboycasey's Avatar
    Join Date
    Jul 2013
    Location
    Fletcher, OK
    Posts
    3,346

    Re: True Total Alkalinity Reading?

    I think you are getting in the weeds unless you really want that kind of info..

    It only matters to drop your TA when your PH is rising fast.. you are trying to stabilize your PH as much as possible to keep around 7.6... so if your pH is doing good then TA of 100 is fine
    Pool: Intex 16x32 15000 gal, 2 speed 340042, Pentair CC320 Filter, CircuPool SJ45 Salt System, Intermatic PE653RC; Hot Tub: 650 Gal SWG Megachlor
    links: pool school * Recommended-Levels * SLAM * CYA chart * Test kits * How To Post Pictures * Poolmath * OCLT ** Support your website if we helped you :) **

  4. Back To Top    #4

    Join Date
    Sep 2014
    Location
    San Ramon, California
    Posts
    65

    Re: True Total Alkalinity Reading?

    Quote Originally Posted by Richard320 View Post
    Who says your alkalinity needs to be reduced by 10?

    If you go to poolmath and go to the last row where it says Suggested Goal Levels and you choose trichlor as your chlorine source (you DO list a Rainbow 320 Chlorinator, after all) recommended TA is 100-120+

    If you're using bleach, then TA suggestion is 70-90+ . You're at 90+ already. You're fine.

    Poolmath takes various forms of alkalinity into account in its calculations. See True Alkalinity Readings or try the search box for more.
    I do list a Rainbow 320 Chlorinator, but stopped using that when it caused problems with my check valves and gas water heater (see - Badly mangled Pentair check valve flapper) about a year and a half ago. So I have been using Liquid Chlorine ever since then. Therefore, the suggested goal TA level stays the same at 70 to 90+ ppm consistent with Pool School. So, the same question I raised above - 'Should I even bother taking the "True Total Alkalinity" formula into account'?
    14,000 gals; IG gunite - Wet Edge Primera Stone finish; Sta-Rite/Pentair Intelliflo variable speed; Sta-Rite/Pentair system3 S7M400 cartrige; Sta-Rite Max-E-Therm 400 heater; (Pentair Rainbow 320 Chlorinator- for vacation use only); built-in automatic pool cover; Trident II UV system (on recall not currently used); built 10/31/2012; TFT-100; MX8 cleaner

  5. Back To Top    #5

    Join Date
    Sep 2014
    Location
    San Ramon, California
    Posts
    65

    Re: True Total Alkalinity Reading?

    Quote Originally Posted by cowboycasey View Post
    I think you are getting in the weeds unless you really want that kind of info..

    It only matters to drop your TA when your PH is rising fast.. you are trying to stabilize your PH as much as possible to keep around 7.6... so if your pH is doing good then TA of 100 is fine
    Yes, my TA was about 120+ ppm about three weeks ago and pH have been inching in the upper bracket faster than I would like. So I have been lowing the TA to get to about 90 ppm (from Pool School Recommended Levels). My thought is to get TA to at most 90 ppm since my City Water source is high on pH to start with.
    14,000 gals; IG gunite - Wet Edge Primera Stone finish; Sta-Rite/Pentair Intelliflo variable speed; Sta-Rite/Pentair system3 S7M400 cartrige; Sta-Rite Max-E-Therm 400 heater; (Pentair Rainbow 320 Chlorinator- for vacation use only); built-in automatic pool cover; Trident II UV system (on recall not currently used); built 10/31/2012; TFT-100; MX8 cleaner

Posting Permissions

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