Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 4 of 4

Thread: Calcium Hardness level in re-plastered pool

  1. Back To Top    #1

    Join Date
    Apr 2014
    Location
    Bakersfield, California
    Posts
    24

    Calcium Hardness level in re-plastered pool

    Just had pool replastered with dark grey colorscapes about 5 weeks ago. Startup was performed by pool service company. After first month pool looks great and all readings are within range. Pool guy said CH was at 235. I tested the following week with Taylor test kit purchased at Leslies and CH was at 380, which was confirmed by Leslies.
    I am now getting a 480 CH reading with my test kit. Leslies is getting a 300 CH reading (as of last Friday).

    Am i doing the CH test incorrectly (Swirling /mix)?

    Could i have bought a test kit with defective CH test liquid?

    Is there a special technique to performing the CH test?

    Could there be something in the fresh colored plaster (calcium additive) that is being released during curing process that could be causing CH reading to increase drastically in such a short period?

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Calcium Hardness level in re-plastered pool

    It is far far more likely that the people at Leslie's are doing the CH test incorrectly than that you are.

    If your sample is turning purple during the test, called a fading end point, the test can read higher than actual. Otherwise it tends to be quite reliable. You might want to review the directions for the test, see the extended test kit directions. Chances are you are doing it correctly, but perhaps there is something there that will help clarify things.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3

    Re: Calcium Hardness level in re-plastered pool

    I'd trust your own tests. My pool was brand new and at the beginning if last summer it was 450 but by the end of the swimming season it was 770. I tried to keep my ph at 7.2 because that suspends the calcium and prevents it from causing scale in your pool. We've had a ton of rain and now I'm at 450 or so again. I think a lot if calcium leached out of my new plaster.
    17,000 inground gunite pool finished June 2013. Pentair variable speed something or another. Polaris cleaner, inline rainbow chlorinator. Using trichlor until CYA reaches 50-60.

  4. Back To Top    #4

    Join Date
    Apr 2014
    Location
    Bakersfield, California
    Posts
    24

    Re: Calcium Hardness level in re-plastered pool

    The calcium leaching out of newly replastered finish makes sense.

    What would explain the big jump in CH from the last time my startup pool guy tested CH (235) to recent CH reading (480) wiithin 1 1/2 weeks ?

    Is it okay to drain some water in the middle of summer to adjust CH without causing any damage to new plaster finish?

Posting Permissions

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