Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: New Member with High CYA, Low FC

  1. Back To Top    #1

    New Member with High CYA, Low FC

    Hi all. I'm brand new to the forum, and also somewhat new to owning a pool. I'm in PA; pool details below. Been using a pool store in my area; anxious to get to BBB. Right now, I've been using A&S Super Pool Treat for shock, and tablets for maintenance. Ordered my test kit, but not here yet. My readings from the pool store:
    FC = .1
    CC = 1.4
    TC = 1.5
    pH = 7.6
    Hardness = 210
    Alk = 100
    CYA = 125
    So, I know my FC is low, and my CYA is high. Water is clear, but I get a little algae around the light. I've read through the info in Pool School, and the CYA/FC chart, but don't fully understand it yet. It says if my CYA is 125, then my target FC is 13.6, and my shock FC is 46.7. How do I convert that to necessary product (bleach) to add? Is the CYA so high, that I'll never get the FC up (and I have to empty some water)?
    Thanks all,
    White plaster, 29k gallons, Pentair Whisperflow 2 HP, Pentair FNS Plus 60 sq ft, AquaCal 120 HeatPump

  2. Back To Top    #2
    svenpup's Avatar
    Join Date
    Nov 2009
    Sacramento, CA

    Re: New Member with High CYA, Low FC

    You can use the Pool Calculator to determine the amounts of chemicals. Setup the "Suggested Goal Levels" type (toward the bottom of the page), pool size (toward the top of the page), and "now" and "target" for each parameter.

    You are correct in your interpretation of the CYA/Chlorine chart, but you really want to drain and refill about 2/3 before you head down this path. You already need to shock based on your CC level and shocking will be impossible with CYA that high.
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock ('s a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  3. Back To Top    #3
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    SouthWest Alabama

    Re: New Member with High CYA, Low FC

    With a CC of 1.4 you need to shock and with your shock level being 47 it's impractical to maintain that level. It would require 16 large (182oz) jugs of bleach just to get you there. And that's not counting how many to keep you there. Since reverse osmosis is not an option in PA, you need to drain about 2/3rds of your water.

    But before you do anything drastic lets wait on your test kit and see what the results are with 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

Posting Permissions

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