Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: how is my pool?

  1. Back To Top    #1

    how is my pool?

    we just got a new gunite pool 20 x 40 free form i have a salt chlorine generator and my test result is this
    free chlorine :4.0
    total chlorine:4.0
    combined chlorine:0
    ph:8.2
    hardness:230
    alkalalinity:110
    cynanuric acid:30
    the pool water is very clear, they told me that my free chlorine is high and my ph is high too, i keep on adding muriatic acid but i don't know what to do for the free chlorine,and how long should i keep out of the pool after putting a quart of muriatic acid in?
    thank you
    ps: i live in northen nj and the pool is in a sunny side,the water temp is usually above 80
    June

  2. Back To Top    #2

    Join Date
    May 2007
    Location
    Houston, Texas, USA
    Posts
    148

    Re: how is my pool?

    Quote Originally Posted by fadouaj
    we just got a new gunite pool 20 x 40 free form i have a salt chlorine generator and my test result is this
    free chlorine :4.0
    total chlorine:4.0
    combined chlorine:0
    ph:8.2
    hardness:230
    alkalalinity:110
    cynanuric acid:30
    the pool water is very clear, they told me that my free chlorine is high and my ph is high too, i keep on adding muriatic acid but i don't know what to do for the free chlorine,and how long should i keep out of the pool after putting a quart of muriatic acid in?
    thank you
    ps: i live in northen nj and the pool is in a sunny side,the water temp is usually above 80
    Your pH is indeed high. As the pool cures, the pH is going to rise. I could take several weeks, even months for it to cure, so until then you will be adding acid frequently. As far as the FC, I'm not sure, but I don't think it's too high. Hopefully some SWG users will be along to shed more light on that.
    Poor Man's Pool
    Doughboy 18 ft round above ground
    7600 gal with center drain
    Pentair sand filter, 1 HP pump
    50 ppm borates
    "I know just enough to be dangerous"
    Pool Calc Ver 1.41 (Excel)

  3. Back To Top    #3
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    FC/TC of 4.0 is not very high. However if want ot bring it down a bit reduce the output of your SWCG. For pH continue adding Muriatic Acid to lower it. It is fairly common for the pH to go up in a new build as the surface cures.
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  4. Back To Top    #4
    thank you
    how about swimming after adding muriatic acid is it harmful and how long should i wait?
    June

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Muriatic acid mixes into the water fairly quickly. I would give it half an hour to an hour with the pump running to mix in before swimming.
    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

  6. Back To Top    #6

    Join Date
    Jul 2007
    Location
    Rockville, CA
    Posts
    99
    My aqualogic/goldline manual shows the ideal range for a swcg pool is 1.0 to 3.0 ppm free chlorine. I have my chlorine generator currently set at 15% and just obtained a reading of 2.6ppm free chlorine with 0 combined chlorine. I had an FC reading of 4.0 at a 25% setting. Check your current setting and drop it down a bit at a time until you reach a level that is appropriate for your pool usage and meets the manufacturer's specifications.
    20K inground gunite w/ Aqua Logic automation and chlorination Sta-Rite 400 K natural gas heater and cartridge filter 2 HP pump 1.5 HP spa bubbler for spillover spa 1 HP dedicated Letro Legend cleaner
    H2O: two parts Heart and one part Obsession. ~Author Unknown

  7. Back To Top    #7

    In the Industry

    Join Date
    Jul 2007
    Location
    Australia
    Posts
    69
    G'day,

    I think your Chlorine is too high and should be brought down to 3 PPM.

    If the high Chlorine was caused by shocking the water, it will
    eventually lower by itself. Otherwise it could be a problem with
    the automatic chlorinator being turned up too high or you have
    the chlorinator running for too long...(your salt levels may be high too?)

    Total Alkalinity is higher than perfect and should be decreased to 100 PPM.

    I Recommended:
    Make sure the automatic chlorinator is working properly.
    Check the Chlorine level and the dial to make sure too much Chlorine isn't coming out.

    * Add Muriatic Acid: 2.4 Gallons (Rough Calculations on 18,500 gallons)

    Test again in 24 hours.

    Hope this helps,

    Take Care,

    Michael Silvester

  8. Back To Top    #8
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    PH is by far the most pressing issue. You should try to keep the PH between 7.2 and 7.8. Since the pool has fresh plaster this is going to take large amounts of muriatic acid added every day or even twice a day for the first couple of weeks. After three or four weels the amount of acid you need to add will go down dramatically and after about a year you won't need to add any more acid because of the plaster (though you might still have CO2 outgassing and need to add acid because of that).

    One of the challenges is that PH higher than 8.2 can often read as 8.2 on the common PH test do there is no way of knowing exactly how much acid you will need. I calculate anywhere from two quarts to two gallons depending on how high the PH really is. I suggest adding two quarts to start and then test the water and add one quart every half hour until your PH gets down to 7.2. Once you have done this a few times you will start to get an idea of how much acid is needed. Keep in mind that the required amount of acid will change as your TA changes, but that should happen slowly.

    Allowing the PH to get really high can result in scaling which can be a great deal of trouble to remove. So it is very important to keep an eye on it.

    TA will come down with the acid addition but go up as the plaster cures. It is fine for now, but eventually you will probably need to lower TA.

    Almost all SWG suggest CYA levels between 60 and 80. You can check your manual to see what they suggest. Higher CYA levels will lower the amount of time the SWG needs to run and extend the cell life. Remember that CYA can take up to a week to disolve, so wait a week before retesting after adding some. Also, CYA is very difficult to lower, so add less than you think you need, wait a week, and adjust from there.

    It would be good to get a good estimate of the pool volume. Free form pools are difficult to estimate. Did your builder give you a design volume? If not, try estimating the average actual width, length, and depth to use for calculating volume.

    Also, fresh plaster should be brushed several times a day.

    Good Luck
    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

Posting Permissions

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