Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: Size of pH chemical additions

  1. Back To Top    #1

    In the Industry
    Aqua Lab Rat's Avatar
    Join Date
    May 2015
    Location
    Anoka, MN
    Posts
    51

    Size of pH chemical additions

    The typical instructions for raising or lowering pH say to add X amount, then retest later. I assume that is so that you don't over-adjust or end up "see-sawing". (That said, I have never overcorrected, it always seems like the doses are about half as much as they should be.)

    Outside of the over-adjustment / under-adjustment issue, and possible cloudiness if you bump the pH up too quickly, is there some other reason to make smaller adjustments, such as creating toxic gasses?
    Lyle
    Professional product developer using & maintaining a dozen or so spas from 150 to 550 gallons, many pools from 1200 to 40,000 gallons (above-ground and in-ground), and a half-dozen test tanks.
    If it's not one thing, it's usually several others!

  2. Back To Top    #2
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Location
    Tucson, AZ
    Posts
    6,513

    Re: Size of pH chemical additions

    For pH adjustments, you need to consider equipment. If you make a large pH adjustment with acid and accidentally mess up the measurement, then you could lower the pH below 7.0 or, worse, crash the TA and have the pH drop precipitously. That is REALLY BAD for anything metallic in the water because pH is the dominant factor in corrosion of metal parts (dissolved oxygen content is the next biggest issue for corrosion). As well, for increasing pH, going too far too fast can mean scaling out calcium carbonate into your equipment. Filter elements can get "limed up" with calcium scale and gas heater cores can develop scale leading to blockages and reduced flow.

    Slow & steady is ALWAYS BETTER than fast & loose when it comes to chemistry....

    PS - And no, you will not create toxic gasses....
    Matt
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

  3. Back To Top    #3

    In the Industry
    Aqua Lab Rat's Avatar
    Join Date
    May 2015
    Location
    Anoka, MN
    Posts
    51

    Re: Size of pH chemical additions

    So it is more for the potential corrosion / scaling issues. Makes sense. Some dosing instructions I have seen put overly strong emphases on it like "DO NOT EVER ADD MORE THAN X" as though it would mean fires, explosions, or Armageddon. In my case, I'm often adjusting test tanks or test spas. In those cases, I'm not too worried that I'll destroy anything but do need to adjust the pH quickly or often to keep it in range for the test. For a consumer who checks things once a week, though, I can definitely understand the reasoning and the need to bring the potential downside to their attention.
    Lyle
    Professional product developer using & maintaining a dozen or so spas from 150 to 550 gallons, many pools from 1200 to 40,000 gallons (above-ground and in-ground), and a half-dozen test tanks.
    If it's not one thing, it's usually several others!

Posting Permissions

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