Become a TFP Supporter Welcome to our new server and new forum software. Pool School
Results 1 to 10 of 10

Thread: what does High/Low Ph do to your skin?

  1. #1
    Senior Member
    Join Date
    Jun 2010
    Posts
    129

    what does High/Low Ph do to your skin?

    just curious to know if a high or low ph will have any effect on our skin...
    24' X 52" round above ground pool---13,500 gallons---Hayward power flow matrix 1.5 hp pump---Hayward 21 in. variflow XL sandfilter---Louisville, Ky

  2. #2
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,658

    Re: what does High/Low Ph do to your skin?

    Yes and no. {EDIT}PH anywhere remotely near the normal range won't do much of anything, but really extreme PH values from straight chemicals before they are added to the water can have some dramatic effects. The rest of this talks about really extreme PH levels (for example straight muriatic acid or lye).{/EDIT} As long as you don't have any cuts nothing obvious will happen right away, but really extreme PH will cause itching. Getting really extreme PH in your eyes can blind you almost instantly, getting in on cuts can be painful, and getting it on mucus membranes can be extremely painful and likely to cause injuries.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. #3
    Senior Member
    Join Date
    Nov 2008
    Posts
    2,598

    Re: what does High/Low Ph do to your skin?

    Jason, how high or low are we talking about to get itchy skin? I assume the other reactions would take even more extreme values.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  4. #4
    Senior Member
    Join Date
    Jun 2010
    Posts
    129

    Re: what does High/Low Ph do to your skin?

    my ph is at 7.2.. im pretty sure this wouldnt cause any skin problems. no one has ever said anything!!!
    24' X 52" round above ground pool---13,500 gallons---Hayward power flow matrix 1.5 hp pump---Hayward 21 in. variflow XL sandfilter---Louisville, Ky

  5. #5
    Senior Member
    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    9,074

    Re: what does High/Low Ph do to your skin?

    The pH of human skin is normally acidic at a pH of around 5.4 to 5.9 (see this link and this link) so having the pool be unusually acidic isn't likely to cause a problem to skin unless it's much more acidic, such as in pools that use Trichlor without adjustment that get down to a pH of 4.5 or lower (i.e. they immediately show red on the TA test). Generally, it takes a fairly low pH below 3 to cause itching -- lemon juice is around a pH of 2.3 and if put on your skin and left to dry you will probably find that it itches.

    Alkaline soap has a pH around 9-10 but can feel slippery on skin rinsed in soft water as some of the soap remains on the skin. If the pH is higher, such as found with lye (13 or higher) or undiluted bleach (11.9 or higher) or chlorinating liquid (12.5 or higher), the oils in your skin saponify which basically turns fats and oils in your skin to soap which is why it feels slippery.

    So generally speaking, a pH range of 7 to 8 isn't going to do very much with your skin unless you have very unusual sensitivities. Tap water is usually in the pH range of 7.5 to 8.0 and is intentionally made more alkaline than neutral in order to reduce metal corrosion.

    Your eyes, on the other hand, are more sensitive to pH changes in the water, but still not that sensitive at least to pH. The pH of human tears varies somewhat but averages 7.5 (see this link while this one says the average is 7.0[END-EDIT]). This paper talks about various factors affecting eye irritation in swimming pools. The primary factor for irritation appeared to be osmotic pressure since adding salt to the water at around 0.5% (around 5000 ppm) in the field study or 0.7% (around 7000 ppm) in the lab study virtually eliminated the irritation which isn't much of a surprise since the salinity of human tears is around 9000 ppm. The pH varying from 7 to 9 did not show a significant difference in irritation. This link describes how the chloramines can be more irritating. Other studies show that nitrogen trichloride (see this link among many others) can be particularly irritating.

    When there is no CYA in the water, then the production of volatile and irritating nitrogen trichloride is much more prevalent, especially with higher bather (or other organic) loads. Also, it is very dependent on the pH where far more is produced at lower pH (from a pH of 8.0 to 7.0 and with no CYA the amount of nitrogen trichloride increases by a factor of 4.3 whereas the active chlorine level increased by a factor of 3.4). So I strongly suspect that the main correlation with eye irritation as well as "bad pool chlorine" smell, coughing and other problems is mostly associated with nitrogen trichloride and that at lower pH more is produced. It isn't the pH of the water itself that is the problem, but rather the effects on the chemistry of what is produced at the lower pH. In pools with CYA in the water, especially in residential pools that typically have low bather load, I suspect that preventing moderate changes in the pH are more important for protection of plaster surfaces and to prevent metal corrosion than for prevention of irritation of the human body.

    Richard
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  6. #6
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,658

    Re: what does High/Low Ph do to your skin?

    I edited my post above to make it clear that I was talking about really extreme PH levels, not something you should ever experience in the bulk pool water.

    For more realistic pool PH levels, PH below 7.2 causes many people to feel some rather mild stinging of their eyes and PH in the low 6s or lower can result in some skin itching and somewhat worse stinging of your eyes.

    Sorry for any confusion.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  7. #7
    Senior Member
    Join Date
    Jun 2010
    Posts
    129

    Re: what does High/Low Ph do to your skin?

    well thats good to know. i try to keep my ph around 7.2 b/c of a stain problem ive had... thanks for the info everyone!
    24' X 52" round above ground pool---13,500 gallons---Hayward power flow matrix 1.5 hp pump---Hayward 21 in. variflow XL sandfilter---Louisville, Ky

  8. #8
    Senior Member
    Join Date
    Nov 2008
    Posts
    2,598

    Re: what does High/Low Ph do to your skin?

    Gosh I just love the experts here!
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  9. #9
    Senior Member NWMNMom's Avatar
    Join Date
    Apr 2007
    Location
    Waaay NW MN
    Posts
    1,574

    Re: what does High/Low Ph do to your skin?

    That was so darned interesting! Thanks so much
    18x33x52 Buttressfree Seaspray (Wilbar) AGP - 1.5hp Pentair Maxim w/22" Pentair Meteor Sand Filter, Aqua Rite SWG System, Biltmore Walk In Steps - 2/4x20 Solar Panel Setup - Pool Rover Jr - finally hard plumbed the whole darned thing -
    Beats Driving to the Lake!

  10. #10
    Junior Member
    Join Date
    Jun 2008
    Location
    Lewisberry, PA
    Posts
    22

    Re: what does High/Low Ph do to your skin?

    Just a little anecdotal evidence, my pool maintained within the proper PH range has no effect on my eyes. However, my well water is off the scale yellow on the PH test, very acidic and stings when I get it in my eyes.
    Roger

    14 x 28 Vinyl Inground, 13200 gal., Hayward EC-65 DE w/1hp Superpump

Posting Permissions

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