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

Thread: Free chlorine problem

  1. Back To Top    #1

    Join Date
    Jun 2014
    Chesterfield Va

    Free chlorine problem

    I am battling a green pool issue. We are just now opening pool and it was treated 2 days ago with 4 bags of biogard burnout 35 as recommended by pool store.

    It is showing some improvement but still green and milky. Went back to pool store for reading and now they say nitrates are at 10...not dangerous they say but said it will be uphill battle fighting algae. Said only way to truly correct is to empty and refill pool.

    Any help or advice would be appreciated. Here is pool info and readings:

    Inground pool. Vinyl, 32'x16'. Approx 14,000 gallons.

    PH: 7.5:
    TA: 114
    Total chlorine: 3.1
    Free chlorine: 0
    Total hardness: 209
    CYA: 40

  2. Back To Top    #2
    pepsiholic's Avatar
    Join Date
    May 2009
    Fairmont, WV

    Re: Free chlorine problem

    First let me recommend that you get yourself a good test kit and take control of the pool yourself. I LOVE, LOVE LOVE, did I say LOVE the TFTest kit sold here. The pool store numbers have a way of being notoriously wrong. If those are truly your numbers then the only thing you need to kill the algae is good old fashioned bleach. There is a method to this and it WORKS! Please read up in pool school on SLAMming your pool and understanding your cya vs. chlorine. It will help you understand the process. I was just in the pool store looking at ladders (didn't buy one, found one online cheaper) and overheard the salesperson telling a lady that she needed to buy this, this, this and this, to clear her pool. I just wanted to scream NOT TRUE (but kept my mouth shut and walked away.) Please read and reread the articles in pool school and the nice people on this forum will be here to help.
    24 x 52 Round AG Outback Empire Pool 13,500 gal.
    1 HP Hayward Power-Flo pump w/Hayward 18" 150lb. sand filter
    TF-100 test kit & SpeedStir
    Wanda the Whale Vacuum

  3. Back To Top    #3
    Richard320's Avatar
    Join Date
    Jan 2010
    San Dimas, CA (LA County)

    Re: Free chlorine problem


    You've made the right first step: you started looking for a better way than the pool store.

    The problem is not Nitrates. The problem is algae. You need to kill it faster than it can reproduce. A pool store shock is but one battle; there's still a war to be fought. You need to knock the algae down and kick it again and again and again so it can't get back up and keep kicking it until it's dead.

    I would suggest you take a look at the ABCs, so you speak the same language as us.
    Defeating Algae explains how to clear the pool. It has links to several other articles.

    The hardest thing you'll have to do is break out the plastic and get a proper test kit. Once you have the test kit, you're in control. Don't expect to find one of the recommended kits in stock at the local pool store; they probably will have a K-2005 DPD tester, and sell it to you saying its the same as the FAS-DPD K-2006, but it's not. Or you can skip that article and just go to and get a TF100 with the XL option (since the pool is green) It is a chunk of change, but it will likely last the rest of this season and halfway into next year, and it will pay for itself with one trip not taken to the pool store.

    Some Inspirational Reading:!
    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

    Join Date
    Jun 2014
    Chesterfield Va

    Re: Free chlorine problem

    Added some bleach last night to shock pool. Kind of greenish still this morning so added more. Looking little better, starting to see some blue but very cloudy still.


    Ph: 6.8
    Ta: 114
    Total chlorine : 3.0
    Free chlorine : 10
    Hardness: 225
    Cya : 50

  5. Back To Top    #5
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Tucson, AZ

    Re: Free chlorine problem

    You need to review the SLAM process in Pool School. Your FC is not nearly high enough for your CYA level.

    How did you get those results? You should fix the pH before raising the FC above 10ppm.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

Posting Permissions

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