Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 13 of 13

Thread: Good CH, still have scale

  1. Back To Top    #1

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Good CH, still have scale

    Performed a chemical analysis this past weekend suspecting CH problems now that I have scale for the first time in 12 years. FC & CC = 13, pH = 7.5, TA = 100, CH = 330, CYA = 120 ( I know this is high and am working to reduce it). So my question is why do I have a scale issue if my CH is within acceptable levels. In addition to scale at the water line, it is also forming as high as 2-3 inches above the water line (like it is leaching up the grout). If my water is balanced , is use of a scale preventer the next step?
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

  2. Back To Top    #2
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,331

    Re: Good CH, still have scale

    Welcome to TFP.

    How did you get those results?
    With the numbers you have, if the pH got up a little your csi would be in the scaling range.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  3. Back To Top    #3

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Re: Good CH, still have scale

    Results were obtained using a TF-100 test kit. I then input the readings into the pool calculator which told me my CSI was ok
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

  4. Back To Top    #4
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,331

    Re: Good CH, still have scale

    Sorry I missed the part about it occuring above the water line.
    Do you know what the salt content is?
    Can you post a picture of it?
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  5. Back To Top    #5
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,085

    Re: Good CH, still have scale

    Will it scrub off with a wet cloth, or does it require muriatic acid to remove?
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  6. Back To Top    #6

    Join Date
    Jul 2011
    Location
    Arizona & California
    Posts
    768

    Re: Good CH, still have scale

    Scaling at and above the water line has nothing to do with the water balance. It is an evaporation issue. Evaporation will deposit all elements in water, such as calcium, sodium chloride, magnesium, etc. Pool water splashing up the tile will also eventually deposit enough scale and become visible. The grout can act as a "wick" for water and scale will form much higher than the water line. A scale preventer would not stop this type of scaling.

    Acid will remove the calcium, but since this type of scale includes additional things other than just calcium carbonate, it is very difficult to remove the other elements.
    If there is water coming from the landscape around the pool and traveling through the pool shell and coming out of the tile, that will also leave a calcium deposit at those places due to evaporation

  7. Back To Top    #7

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Re: Good CH, still have scale

    To Bama Rambler and John T: not a salt pool, and it took acid to get it off although the grout still has a whitish residue. Deposits on the tile were removed with a combination of acid, followed by scrubbing with scotchbrite, followed by a putty knife to remove the stubborn deposits.

    To on Balance (the expert!): I don't think water thru the shell is an issue since I only use drip irrigation very sparingly. Is there any additive I can use in the water to minimize the effects of the other elements you refer to?
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

  8. Back To Top    #8

    Join Date
    Jul 2011
    Location
    Arizona & California
    Posts
    768

    Re: Good CH, still have scale

    Sorry, but all water contains magnesium, sodium, chloride, and especially calcium. There is nothing that can be added to the water that would remove those elements. They will deposit out when evaporation takes place. There is no way out of that fact. Only distilled water is free of these elements. Adding a chlorine sanitizer continually adds more sodium and chloride, and sometimes other chemicals. As the amount of total dissolved solids (TDS) increases over time, more of a noticeable deposit on tile will occur.

  9. Back To Top    #9

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Re: Good CH, still have scale

    Thanks--I look forward to many more hours of scrubbing!!!
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

  10. Back To Top    #10

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Re: Good CH, still have scale

    One more question on this topic. Is the purpose of scale inhibitor to slow down the calcium build up where it is not feasible to replace the water with more pure water? If not, what is its purpose? Thanks
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

  11. Back To Top    #11

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

    Re: Good CH, still have scale

    Yes, you are correct. The purpose is to inhibit scale formation though as the CH climbs it will take higher levels of calcium sequestrant / scale inhibitor to prevent scaling and at some point you just need to dilute the water to get the CH lower. However, I'm not sure how well such products would work against preventing scale from splash-out/evaporation since the concentration gets very high in that case. They might help only in that they may prevent a "hard" scale from forming if they are designed to interfere with the crystal formation.
    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"

  12. Back To Top    #12
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: Good CH, still have scale

    I only want to second onBalance and chem geek.

    There is no product made or that can be made to stop scale from forming where water wets something and then evaporates.

    Scale inhibitors only work on/in areas that are constantly wet or submerged. Only then do they work when everything is kept in balance with pH, TA, mineral saturation, and temperature.
    This is just one of those unfortunate absolutes that can't be changed.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  13. Back To Top    #13

    Join Date
    Sep 2013
    Location
    DFW area
    Posts
    8

    Re: Good CH, still have scale

    OK--thanks a bunch
    22,000 gal, DE, IG PebbleTec, Pentair Intelliflo. Texas (DFW area). TF-100

Posting Permissions

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