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

Thread: pH testing with high Chlorine

  1. Back To Top    #1

    Join Date
    Mar 2008
    Location
    Lake Forest, CA
    Posts
    110

    pH testing with high Chlorine

    I apologize if this has been covered several times here already.....

    Using my Taylor K-2006 kit, if I want to test for pH when I've got the chlorine level up high (20 ppm or more), can I add a drop or two of thiosulfate (R-0007 in the Taylor kit) to the water sample before adding the drops of R-0004, and expect the pH test to work?

    Thanks,
    Greg
    12000 gal IG pool/spa combo,60 sq ft Jandy DEL filter,2 hp Jandy Stealth pump,Jandy LX400 400K BTU gas heater,Pentair Rainbow 300 off-line feeder (never gets used),Jandy Aqualink RS4 with PDA remote,3 Jandy 12" sheer descent waterfall features, Dolphin Oasis Z5 robotic cleaner

  2. Back To Top    #2

    Join Date
    Feb 2008
    Location
    Flower Mound, TX
    Posts
    5,062
    Good question! I would also be interested in knowing the answer to this one.
    10K gallon IG gunite with waterfall; Pentair CC320P filter; WhisperFlo 2 HP pump
    TF Test Kits - Pool Math - Pool School
    "It depends."- JohnT

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Yes, and no. Adding thiosulfate will neutralize some or all of the chlorine but the thiosulfate will also shift the PH a bit. The result is usually better than without the thiosulfate but it reduces the precision significantly.
    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

  4. Back To Top    #4
    Guest
    In a word, no. Adding thiosulfate will causes the pH of the sample to rise so you will not get an accurate ph reading. Either way (with or without the thiosulfate) the pH is going to read higher than it really is. You CAN use a properly calibrated pH meter (the keywords here are properly calibrated) to get a more accurate pH reading but why worry about it.I know people get stresses out about having the chlorine be most effective when shocking by having the pH low but unless you start out with VERY high pH, in actual practice it's not going to be THAT much of a problem. Remember, It's a pool, not rocket science!

  5. Back To Top    #5

    Join Date
    Mar 2008
    Location
    Lake Forest, CA
    Posts
    110
    Thanks for the replies. I really wasn't all that concerned or stressed out about it, just curious if I could measure pH with high chlorine and not be wasting my time. Now I know not to bother, which is good information. I did lower the pH to about 7.2 before starting anyway. Thanks again for the help.

    Greg
    12000 gal IG pool/spa combo,60 sq ft Jandy DEL filter,2 hp Jandy Stealth pump,Jandy LX400 400K BTU gas heater,Pentair Rainbow 300 off-line feeder (never gets used),Jandy Aqualink RS4 with PDA remote,3 Jandy 12" sheer descent waterfall features, Dolphin Oasis Z5 robotic 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
  •