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

Thread: Question Regarding CYA

  1. Back To Top    #1

    Join Date
    Aug 2016
    Location
    HICKSVILLE, NY
    Posts
    87

    Question Regarding CYA

    I've had this pool for 15 years, but this is the first year that I've been closely monitoring the chemistry (just spent 3500 on a new heater). CYA has been steadily inching up to 120. After downloading the Pool Calculator and plugging in today's readings, I realized that with CYA at 120, the amount of FCL required to properly sanitize the water goes up to the 9-15 range. I had been maintaining it between 3 and 5. Am I understanding this correctly?
    28,000 gallons, 18x36, vinyl liner
    Hayward C4030 Cartridge Filter, Hayward TriStar VS 900 Pump, Raypak 400 BTU gas heater,
    Stenner 45mhp10 Peristaltic Pump (for bleach injection)
    2 skimmers, 2 returns, main drain, Lamotte ColorQ and TF-100 test kits

  2. Back To Top    #2
    Mod Squad Jimrahbe's Avatar
    Join Date
    Jul 2014
    Location
    Bedford, TX
    Posts
    5,354

    Re: Question Regarding CYA

    Tom,

    Here is a chart showing the relationship.. Chlorine CYA Chart

    The chart only goes up to a CYA of 100, so your 9 to 15 FC level sounds about right. I suggest you replace enough water to get your CYA in the 40 ppm range. Might have to do that is stages so you don't have to drain too much at once.

    With an FC of 10 your pH testing will be inaccurate.

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Calder Spa.

  3. Back To Top    #3

    Join Date
    Aug 2016
    Location
    HICKSVILLE, NY
    Posts
    87

    Re: Question Regarding CYA

    Agreed. I drained 13 inches to start. By my calculations, that's about 5300 gallons, or about 19% of the pool. That should bring me just below 100 CYA....hopefully. Thanx.
    28,000 gallons, 18x36, vinyl liner
    Hayward C4030 Cartridge Filter, Hayward TriStar VS 900 Pump, Raypak 400 BTU gas heater,
    Stenner 45mhp10 Peristaltic Pump (for bleach injection)
    2 skimmers, 2 returns, main drain, Lamotte ColorQ and TF-100 test kits

  4. Back To Top    #4
    Mod Squad YippeeSkippy's Avatar
    Join Date
    Jan 2012
    Location
    'burbs of Augusta, Georgia
    Posts
    6,491

    Re: Question Regarding CYA

    Tomolena- how do you sanitize your pool? Are you using products which continually keep adding more CYA to your water, like pucks or powder?

    Yip
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

Posting Permissions

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