Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Ph problem with New Plaster

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    Houston, TX
    Posts
    5

    Ph problem with New Plaster

    This is my first post. Great site!. I've been following it for two months and I really like it.
    I had my pool replastered (1st time on a 21 year old pool) on May 24. The plaster contractor gave me start up procedures from the National Plasterers Council - 2 pages with the "NPC" logo in the background in large blue letters. I believe I've seen it on this site.
    The procedures say to adjust the ph to 7.2-7.6. My readings using a TF-100 kit are: ph 8.2, TA 80, CH 225, FC 1. On day 1 (May 25)
    I put in acid three times - 28, 40 and 40 oz. per the pool calculator on TFP. My acid is old- at least 4 or 5 years. Today (May 26) the ph is still 8.2 and maybe higher since the test kit only goes to 8.2. Should I get new acid and try again or is something else going on?
    Thanks for your help!
    16500 gal IG gunite/white plaster
    DE filter TF-100 Test Kit
    Now using bleach

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

    Re: Ph problem with New Plaster

    Welcome!

    If the dosages poolmath kicked out went up each time, that means the TA went up, which is common in new plaster. Assuming it's muriatic acid you're using and it still smokes a little and irritates your eyes and lungs when the wind shifts like it always does, it's probably still good and things are normal. At the rate you're going through it, you'll be needing to buy more acid soon anyway.
    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
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    9,004

    Re: Ph problem with New Plaster

    At that rate of application, what you have won't last long anyhow. Use PoolMath to see what effect those additions SHOULD be making, test again in 30 minutes and adjust your results. What you have is probably just fine though. What Baume are you using? Welcome to the forum.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
    Margaritaville Frozen Concoction Maker, Liqour Chiller, & Drink Mixer & Party Tub----Collect 'um all!

  4. Back To Top    #4

    Join Date
    May 2014
    Location
    Houston, TX
    Posts
    5

    Re: Ph problem with New Plaster

    Quote Originally Posted by woodyp View Post
    At that rate of application, what you have won't last long anyhow. Use PoolMath to see what effect those additions SHOULD be making, test again in 30 minutes and adjust your results. What you have is probably just fine though. What Baume are you using? Welcome to the forum.
    20 Baume/31.45%. So I should keep testing and adding acid every hour or so until the ph comes down? A whiff of my acid is irritating, so it is probably ok.
    Thanks again.
    16500 gal IG gunite/white plaster
    DE filter TF-100 Test Kit
    Now using bleach

  5. Back To Top    #5

    Join Date
    May 2014
    Location
    Houston, TX
    Posts
    5

    Re: Ph problem with New Plaster

    Quote Originally Posted by Richard320 View Post
    Welcome!

    If the dosages poolmath kicked out went up each time, that means the TA went up, which is common in new plaster. Assuming it's muriatic acid you're using and it still smokes a little and irritates your eyes and lungs when the wind shifts like it always does, it's probably still good and things are normal. At the rate you're going through it, you'll be needing to buy more acid soon anyway.
    Dosages went up because on the first dose I was attempting to lower ph to 7.4. On the next two I was trying to lower ph to 7.2. Each time when I checked later the ph was still at 8.2. It was like the acid I put in had no effect. I have not seen a ph reading lower the 8.2 yet. Also, the TA has not increased. When I filled the pool up (Houston public water) and checked the TA it was 90. I then added Jack's Blue Stuff as the sequestering agent. TA was 80-90 when checked later that day. Today when I checked the TA first thing it was 80.
    So, this afternoon I went and bought new acid and added 19 oz per Poolmath to try and lower the ph to 7.6. I will see if this helps.
    Thanks
    16500 gal IG gunite/white plaster
    DE filter TF-100 Test Kit
    Now using bleach

  6. Back To Top    #6
    Divin Dave's Avatar
    Join Date
    Oct 2013
    Location
    Longview, Texas
    Posts
    4,926

    Re: Ph problem with New Plaster

    Tommykat,
    The test kit can only test up to the 8.2 mark. It cannot test for higher than that. And so if the test says it's 8.2 does not mean thats what the pH actually is. Your PH was way above 8.2. Thats why you didnt see a change in the PH test yet

    Once you get enough MA in there to drop the pH to a testable level, you will definitely see it change and be able then to zoom in it.

    Couple days ago someone else expereinced the same thing. They had to put in more than a gallon to get the pH down
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

Posting Permissions

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