Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: Seemed like a good thing at the time.

  1. Back To Top    #1

    Join Date
    Apr 2015
    Location
    Camarillo, CA
    Posts
    32

    Seemed like a good thing at the time.

    I needed to add a gallon of acid to my pool today. I have a 3-4' high tile wall spilling into a surge pond for the pump suction. There was some calcium build up on one section of the tile wall so I poured the acid down the wall to burn off the calcium. I used 14.5% HCL (Muriatic Acid) and now wondering if this is not advised. I flushed the tile afterwards and the acid removed the calcium very nicely. I expect it is probably doing some damage I didn't see. The surge pond is probably about 250 gallons so the pH dropped pretty low in the surge until it was all flushed out. What other damage might I be doing with pouring acid on a tile wall?
    April 1, 2015 first fill of infinity edge of about 15,000 gallons. Aqua Blue Pebble Sheen, iAquaLink, Jandy 2 HP variable filter pump, Jandy 2.5 HP single speed feature pump, Jandy CL580 cartridge filter, Jandy heat pump, Jandy propane heater, spa of unknown size, 3 LEDs in pool, 2 LEDs in surge pond and 1 LED in spa, Eclipse EC-10 Del Ozone oxidizer and 4 Jandy laminars with Jandy CS100 filter built by California Pools in 2015.

  2. Back To Top    #2
    Mod Squad woodyp's Avatar
    Join Date
    Apr 2010
    Location
    East Texas
    Posts
    8,995

    Re: Seemed like a good thing at the time.

    You'll probably be just fine with that lower % MA, but I sure would have cut it 50/50--brushed it-- and worked my way up from there to be cautious.
    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!

  3. Back To Top    #3
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Location
    Tucson, AZ
    Posts
    11,584

    Seemed like a good thing at the time.

    Muriatic acid is a strong acid as opposed to vinegar which is a weak acid. A 10% (9 parts water to 1 part acid) solution of MA has a pH = 1. So it doesn't take much to make a very acidic solution.

    Your ceramic tile is probably fine but you need to be careful about grout as it is mostly just cement and cement is easily etched and removed by MA.


    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 Dolphin S300i robot, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

  4. Back To Top    #4

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,082

    Re: Seemed like a good thing at the time.

    Actually, a 10:1 dilution of full strength Muriatic Acid (31.45% Hydrochloric Acid) is a pH of 0, not 1. This is because the pH of full-strength Muriatic Acid is -1 so a 10:1 dilution raises this by 1 unit to a pH of 0.
    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"

  5. Back To Top    #5

    Join Date
    Apr 2015
    Location
    Camarillo, CA
    Posts
    32

    Re: Seemed like a good thing at the time.

    Great ideas! I'll cut the acid with water before pouring on the calcium deposits and scrubbing next time. Thanks!
    April 1, 2015 first fill of infinity edge of about 15,000 gallons. Aqua Blue Pebble Sheen, iAquaLink, Jandy 2 HP variable filter pump, Jandy 2.5 HP single speed feature pump, Jandy CL580 cartridge filter, Jandy heat pump, Jandy propane heater, spa of unknown size, 3 LEDs in pool, 2 LEDs in surge pond and 1 LED in spa, Eclipse EC-10 Del Ozone oxidizer and 4 Jandy laminars with Jandy CS100 filter built by California Pools in 2015.

  6. Back To Top    #6

    Join Date
    Mar 2015
    Location
    Upland, CA
    Posts
    222

    Re: Seemed like a good thing at the time.

    Quote Originally Posted by chem geek View Post
    Actually, a 10:1 dilution of full strength Muriatic Acid (31.45% Hydrochloric Acid) is a pH of 0, not 1. This is because the pH of full-strength Muriatic Acid is -1 so a 10:1 dilution raises this by 1 unit to a pH of 0.
    Is that negative pH a calculation based on the molarity? I would think that the "real" pH might be a bit higher if the H+ ions weren't fully dissociated.
    20k gal. IG plaster w/spa. 2 HP Aqua-Flo "A" pump, Hayward DE6020 filter. "The Pool Cleaner".

  7. Back To Top    #7
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Location
    Tucson, AZ
    Posts
    11,584

    Re: Seemed like a good thing at the time.

    Quote Originally Posted by sbcpool View Post
    Is that negative pH a calculation based on the molarity? I would think that the "real" pH might be a bit higher if the H+ ions weren't fully dissociated.
    Chemgeek, as always, is quite right. My original comment was based on faulty math.

    HCl is a strong acid with a very large Ka. The assumption that the [H+] = [HCl] is accurate even at very high concentration like what is found in commercial grade HCl. The technical reason is that the chloride ion (Cl-) is an extremely weak conjugate base so all of the protons from the HCl dissociate to form the hydronium ion (H3O+).

    So yes, 31.45% HCl has a pH = -1


    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 Dolphin S300i robot, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

Posting Permissions

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