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Thread: first test with tf-100

  1. Back To Top    #1

    Join Date
    Jun 2011
    nashville, Tennessee

    first test with tf-100

    My pool water is clear. I just spent a week getting rid of all the algae I had by maintaining shock levels. (just by adding 3 pucks every other day). I am using 3 inch tri chlor tabs (I have about 10 left). Current levels are
    fc - 12
    cc -1
    tc - 13
    ta - 90
    ch - 270
    cya - 60
    ph - 7.2

    The pool calculator says to use 55oz borax, 40 oz baking soda, and replace 30% of my water.

    1. I dont really want to replace 30% of the water, is this absolutely necessary?
    2. Also should I do the baking soda or borax first or does it matter?
    3. Should I pour all the chemicals in at once or do half, retest, and then do the other half if necessary? I dont want to put in too many chemicals and I also dont want to waste my testing kit. Pool school says borax will raise TA slightly so Im not sure if I need to use the full amounts from the pool calculator.
    4. Do I just pour them into the skimmer? Or do I put them in a sock? Or do I put them in front of the return? Can I just dump them in, or do I have to pour them slowly?

    Thank you for any help you can give me. I want to take care of the pool and not let it ruin my summer.
    27 ft round above ground pool. Vinyl liner. 17k gallons. 2hp pump sand filter.

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

    Re: first test with tf-100

    Welcome to TFP!

    Keep in mind that the Pool Calculator is designed to tell you how to accomplish your goals, not what your goals should be. There are some numbers in the target column, but they aren't universal and are supposed to be replaced with the values you are trying to achieve.

    I suspect it is saying to replace water because of CYA. While your CYA is higher than I would recommend, it isn't high enough to warrant replacing water at this time. A better thing to do would be to think about stopping using tablets, which are going to continue raising CYA until it eventually becomes a problem.

    Raise the PH first, then test the TA again and see if it still needs to be raised.

    Adding about 2/3rds of the recommended amount, let it mix in, and then test again to see where you ended up, is a good approach for large changes. For smaller changes go ahead and add it all at once.

    Different chemicals get added in different ways. CYA gets put in a sock. Liquids get poured in front of a return with the pump running, most powders get pre-dissolved in a bucket and then poured slowly in front of a return.
    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

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