Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Can CH be too low?

  1. Back To Top    #1

    Join Date
    Jul 2007
    Location
    deep in the piney woods of southern Alabama
    Posts
    2

    Can CH be too low?

    Howdy Folks,

    Thanks for a marvelous forum! I’ve learned more about water chemistry in the last 2 weeks than in a lifetime of messing around with pools and spas. The wealth of knowledge here along with my new TF100 test kit (thanks, Dave) has finally allowed me to see exactly what’s happening and why I’ve had various problems over the years. I am the very definition of “pool stored.” It’s rather embarrassing actually …

    Here’s my first set of numbers:

    FC = 17 (had just done the superchlorinate thing with the SWG)
    CC = 0
    PH = 7.8
    CYA = 100+ (black dot disappears completely before it gets to the 100 line)
    TA = 200
    CH = 30 (this area is known for soft water and high alk)

    I shocked it because the steps and liner began to feel a little slimy. After 2 days at FC = 17, the slime is gone and FC holds steady over night.

    Next I went to work on the CYA. I would have to say that understanding the relationship between CYA and the level of disinfecting chlorine is probably the single most liberating bit of knowledge a pool person can have.

    I replaced about 12”of water over the weekend and then I began working on lowering the TA:

    FC = 11
    CC = 0
    PH = 7.2
    CYA = 80
    TA = 170
    CH = 30

    I have 2 questions please:

    1. Should I do anything about the low CH?

    2. What should I do when the Nature2 cartridge expires in the DuoClear? Can I just forget about it or does it need to be removed and the housing capped off in some way? I can probably make a cap from the old cartridge.

    Thanks again. This is actually fun now that I understand a little bit about what’s going on.
    10x20 6700 gal IG Vinyl
    Hayward 3/4HP pump and sand filter, Zodiac DuoClear SWG
    SI/Aquatherm solar collectors with Goldline control

  2. Back To Top    #2
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045
    Hi Bill,

    Just wanted to say Welcome to TFP! It does feel really good not to get 'pool stored' doesn't it!

    Joyce
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Welcome to TFP!

    With a vinyl liner and no spa there is no need for CH, so no need to worry about it being low.

    You can always leave an expired cartridge in without a problem. With most models you can remove the cartridge and everything will be fine.
    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

  4. Back To Top    #4

    Join Date
    Jul 2007
    Location
    deep in the piney woods of southern Alabama
    Posts
    2
    Thanks for the warm welcome!

    I got in trouble by:

    Adding too much conditioner (as per PB's instructions)
    Running high Ph (PB said don't worry about it unless it gets to 8.0)
    Maintaining FC between 0.5 and 1.0 (as per DuoClear instruction manual)

    Between the PB and Zodiac, I never had a chance ...
    10x20 6700 gal IG Vinyl
    Hayward 3/4HP pump and sand filter, Zodiac DuoClear SWG
    SI/Aquatherm solar collectors with Goldline control

  5. Back To Top    #5
    Guest
    The main reason to keep the CH at around 130 ppm or higher in a vinyl pool is to help prevent foaming. Soft water will foam more readily that hard water if there is any organic load in it.

Posting Permissions

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