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

Thread: What to adjust first?

  1. Back To Top    #1

    What to adjust first?

    We opened our 39,000 gal vinyl liner pol last summer. After setting all winter it's a dark green mess and u cant see 6" into the water. I know the bottom is covered in leaves since last Fall. I tested the water with the cheap hth brand test strips and readings as followed:
    FC: 0 Ph: 6.4 TA: 120 TH: 200 CYA: 0
    which do I adjust first? Do I Shock the pool (using Cal-Hypo) and then add Cyanuric Acid and Soda Ash or do I fix the Ph before shocking and see if the CYA levels come up on their own after shocking it, as I'm pretty sure I remember reading Cal-Hypo raises CYA levels. Thanks!

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

    Re: What to adjust first?

    Welcome to TFP!

    Start by raising the PH to 7.2.

    Then start raising CYA.

    Add 2 ppm of chlorine each evening until 24 hours after you start adding CYA, at which point you switch to targeting the appropriate FC level for your CYA level.

    In the long run you may want to work on lowering TA, but only if PH is constantly going up.
    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
    Richard320's Avatar
    Join Date
    Jan 2010
    San Dimas, CA (LA County)

    Re: What to adjust first?


    First thing: ditch those test strips. They won't cut it. You need a proper test kit. For a pool as big as yours and being a green swamp, you want a TF100 with the XL option. I make no money off this, it's what I use. A long writeup explaining why it's the best deal is here.

    Second, read some other articles in pool school, chiefly ABCs and SLAM

    Third, physically remove as much debris from the pool as possible, even working blind with a leaf rake or leaf bagger.

    Fourth, adjust pH after taking readings using your proper test kit. Add CYA if needed to get to 30 or so and then start adding chlorine to kill it, just like the SLAM article says. Pay attention to the prerequisites listed in that article.

    For some inspiration, check some other threads. I need to organize it again, but you'll find some good ones in this thread:
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  4. Back To Top    #4

    Re: What to adjust first?

    Jason and Richard, thank you both for your response. Ill try exactly that. Il keep reading until I have a better understanding of all this. Planned on buying a better test kit already after reading through website a bit earlier. I'll try the one you recommended! Thanks again!
    Steven V. 39,000 gal IG vinyl liner pool: Pentair Tagelus TA 60/60D filter; Pentair Challenger 1 HP pump motor; currently using hth test strips

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

    Re: What to adjust first?

    Welcome to TFP!

    First, the previous responders gave you good advice. I would follow it.

    Quote Originally Posted by Steven Vickery
    Do I Shock the pool (using Cal-Hypo)
    We recommend using liquid bleach (the plain unscented, no thickeners added stuff) for chlorine.

    Also, suggest adding info about your pool to your signature. It would help us give more targeted advice for your pool.
    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.

Posting Permissions

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