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

Thread: CH question

  1. Back To Top    #1

    CH question

    My CH level is continuing to creep up for some reason. About 6 weeks ago it was 280 and now it is around 350. In that time period other than adding bleach, muratic acid, and the occasional baking soda, I haven't added anything else. What is causing it to rise and how high is too high before I need to replace water. Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?

    Thanks for any help.
    10,000 Gallons/Cartridge Filter/In Ground/Plaster

  2. Back To Top    #2
    Smykowski's Avatar
    Join Date
    Sep 2011
    Location
    Gurnee, IL (North Suburban Chi-town)
    Posts
    3,065

    Re: CH question

    1. Is your pool new?

    2. Have you tested your fill source?
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
    The most important article on this site - The ABCs of Pool Water Chemistry

  3. Back To Top    #3

    Join Date
    Jul 2013
    Location
    Columbus, Ohio
    Posts
    114

    Re: CH question

    Quote Originally Posted by Fletch03
    My CH level is continuing to creep up for some reason. About 6 weeks ago it was 280 and now it is around 350. In that time period other than adding bleach, muratic acid, and the occasional baking soda, I haven't added anything else. What is causing it to rise and how high is too high before I need to replace water. Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?

    Thanks for any help.
    Have you tested your fill water for CH? CH and CYA only drop when you replace liquid water. Evaporation leaves CH and CYA behind in the remaining water. I don't think your CH is cause for concern but I know more about CYA than I do CH in a plaster pool. Mine is vinyl and I don't worry about CH too much.

    Compare the CH level of your fill water to your pool just to see if you fill water is higher.
    16,500 gallon, 18" x 38" Grecian; IG Vinyl, Hayward DE

  4. Back To Top    #4

    Re: CH question

    Yeah the pool is about 2 months old. I'll check fill water but when I originally filled up the pool I want to say CH was around 160 or so, so I don't think it is fill water.
    10,000 Gallons/Cartridge Filter/In Ground/Plaster

  5. Back To Top    #5
    BoDarville's Avatar
    Join Date
    Jun 2012
    Location
    DFW, Texas
    Posts
    3,840

    Re: CH question

    Quote Originally Posted by Fletch03
    Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?
    Not necessarily. Water evaporates, but CH does not. When you refill, you are adding some additional CH even if your fill water is lower in CH than your pool water. The water again continues to evaporate, you top off, and the cycle repeats. What you are experiencing is quite common. I experience the same thing. MY CH is the same as yours and is no cause for concern (it is in the high end of the recommended range). Still worth testing the CH of your fill water to see where it is at. The CH will drop if rainfall picks up as rain water has no CH.
    Gold Supporter, TFP Lifetime Supporter, 26,680 gal Plaster IGP 3.5 - 10' depth / Attached Waterfall Spa, Manually Chlorinated, Triton Sand Filter, 1.5 HP * 1.1 SF = 1.65 SFHP 1-speed Pentair WhisperFlo WF-26 Pump, 400K BTU NG Teledyne Laars Series One Heater, Polaris 360, Test Kit Comparison, Chlorine/CYA Chart, SLAMing Your Pool, OCLT
    A good test kit is an investment, not an expense.

  6. Back To Top    #6

    Re: CH question

    The new plaster may be adding CH. Use the pool calculator, and see what your CSI is. You want to keep this slightly positive to protect your new plaster while it cures. Yours isn't rising very quickly though; if your CSI is on the positive side, just make sure it stays that way.
    Outdoor 14,000 gallon IG plaster pool built in 2000 with spillover spa, 2 hp WhisperFlo pump with MagneTek motor, Sta-Rite cartridge pool filter with 300 ft2 filtration area and 0.33 gpm/ft2 filtration rate, Aquabot Rapids 4WD robotic pool cleaner, Raypak digital gas heater, and Intermatic mechanical timer located in the Dallas-Fort Worth metroplex

Posting Permissions

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