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Thread: I added muriatic acid...

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    I added muriatic acid...

    These are the test results yesterday
    FC 15ppm
    CC .5
    TC 15.5
    TA 170

    Yesterday I added 15 oz muriatic acid according to pool calculator. I did that for pH. That's the correct thing to do for pH, right? Since I was away from the house I just let the pool pump run for several hours. I also added a little water since the level was a little lower (it is already over 90 degrees in the afternoon where I live). The pool pump ran for 6 hours last night, and the SWG for 3 hours.

    Today I tested and got
    FC 13
    CC .5
    TC 13.5
    pH appears to be a little lighter than 7.5, but not yet 7.2
    TA 170
    I am assuming the CYA is still 80 which is what it tested on 5/28. Can I make that assumption?

    Did FC drop due to muriatic acid too? Am I doing okay? I imagine I should add more muriatic acid? I plan on a small pool party Friday evening, and I would like to know that my water is healthy. I have time to adjust still, so advice anyone? Thank you.
    Intex 20'x10'x52" 5,835 gallon above ground; vinyl; Intex 2,650-Gallon Sand Filter Pump; Intex Krystal Clear Saltwater System Model CS8110.

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    Re: I added muriatic acid...

    How does your water look?
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  3. Back To Top    #3

    Re: I added muriatic acid...

    First, you are doing fine. No more Muriatic Acid (MA) just yet. Concentrate on learning how much chlorine you need in a typical day. Reducing TA is not that important, it is sort of fine tuning to keep your pH in line.

    Second, the FC drop of 2 ppm is about what you expect over a 24 hour period in the sun and heat. Let it drop some more.

    Earlier, in the other thread, Jason Lion said,
    You are good to swim!

    2) When PH gets up to around 7.6 to 7.8, lower it back down to around 7.2 to 7.4.
    3) For normal day to day use, FC should be between 6 and 11, and never lower than 6.
    4) Follow the steps I mentioned in #2 above and TA will come down over time. You could be more aggressive about lowering the TA, but I thing this simple procedure will be much simpler.
    I wonder if he missed that this is a SWG pool. At CYA 80, in SWG pool, you want FC to be in the range of 4 - 6.

    So, for now, don't worry about if the pH did not get all the way to 7.2. Let it rise to 7.6 or 7.8 before you push it down again.

    Now I do wonder why it did not get as low as you wanted. But then, it may have actually gone to 7.2 but risen by morning, you see. If it did, then when you test again, you may see that TA has gone down some, maybe by 10 or so. I wouldn't rush this lowering of the TA, just get around to it gradually. When it hits 7.7 or so, lower it to 7.2. And do test the TA before you add MA again, just in case it has lowered by a lot. It will affect the volume of MA you use for a given pH drop.

    But, back to the chlorine. For the SWG pool, you want to be between 4 and 6, so let it drop down now. No more bleach if you were using that and you may need to turn down the SWG a bit more, I dunno.

    For swimming, we find that pH of 7.5 to 7.8 is just fine for the eyes. So, don't be playing with the pH too much when you will have guests. And, depending on where you are located, if your fill water has high TA (mine is 340) then everytime you add water the TA goes up a bit. So, I expect to add MA all the time, maybe a little, maybe a lot, depending on how fast my pH is rising to 7.8 and how much water I've been adding.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

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    Richard320's Avatar
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    Re: I added muriatic acid...

    If I remember what I've read right, pH is not entirely reliable with FC that high.
    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.
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    Re: I added muriatic acid...

    Quote Originally Posted by Richard320
    If I remember what I've read right, pH is not entirely reliable with FC that high.
    Oh, that is right! No more testing of pH until the FC is below 10. Therefore no more MA.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  6. Back To Top    #6

    I will turn SWG to 2 hours

    Thank you for your replies. I went to church so I just saw your posts. I had not added liquid chlorine, so I will turn SWG down from 3 hours to 2 hours and hopefully that will bring FC down. When it gets to 5, should I bump it back up to 3 hours? If the appropriate range is 4-6, then if goes below 4 it is unsafe to swim?

    My water is very clear.

    So I'm okay then except for trying to get the FC down, right? The pH might drop on its own after having guests?

    If I'm getting all of this right - what I really want to concentrate on is keeping my FC between 4-6 and try to get and keep my TA between 70 and 90? If I can do those two things, then the other things kinda fall into place?
    Intex 20'x10'x52" 5,835 gallon above ground; vinyl; Intex 2,650-Gallon Sand Filter Pump; Intex Krystal Clear Saltwater System Model CS8110.

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    Re: I added muriatic acid...

    If I'm getting all of this right - what I really want to concentrate on is keeping my FC between 4-6 and try to get and keep my TA between 70 and 90?
    Just keep replenishing the chlorine to keep it at that level. The TA, CH, pH, and CYA are fairly stable and should not move much.

    Keeping the proper level of chlorine in your pool is the most important parameter and the one that will change daily.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: I added muriatic acid...

    Look here at the CYA charts
    http://www.troublefreepool.com/pool-...ya_chart_shock

    See the SWG chart, at CYA 80 your target FC is between 4 and 6 and shock is at 30. You can swim at less than 30, it's OK. when things are normal you shoot for FC of 5, give or take one. So if it gets below 4 turn it up to keep it above 4 but don't bother going beyond 6 if you can help it.

    Now, if Duraleigh or anyone else says different, I bow to their superior knowledge. I'm just a novice around here, but I read a lot.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

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