Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: Veryifying plans

  1. Back To Top    #1

    Join Date
    Mar 2012
    Location
    Lewisville, Texas
    Posts
    71

    Veryifying plans

    Just want to verify how much pH will lower with CYA. I'm probably going to start with 10 CYA to test how fast we lose it because I still have one verified leak we aren't quite ready to fix until fall/winter at the earliest.

    If it doesn't lose too much after a week we'll probably up the number up to the recommended 30. The pH is currently 7.6 with a TA of 80 and CH of 380 with TDS at 800..Total dissolved solids..not sure what that entails exactly, but I listed since its on the pool test I got from Leslies.

    I know from prior reading that TA and pH are related in regards to acid changing pH...or at least thats the impression I got, but I'm not completely sure how much change to expect.

    Thanks for any input on what I should do. pH is just about perfect where it is so if getting it to 10 and than 30 won't effect it that much I guess I can go ahead and leave not mess with the pH after adding the CYA. Considering the pH of the fill water when last tested was 8.0 it will likely trend up over time when we have to readd due to water evaporation...but the rate of loss is certainly less than before we fixed 2 other leaks so that'll probably be at least a month.
    Lewisville, Texas 22,000 Gallon IG Plaster Chlorine FNS Plus Vertical Grid D.E. Filter 60 sq. ft. 150 GPM Push/Pull Valve Hayward Ecostar SP3400VSP Baracuda Zodiac G3 Cleaner

    Caldera Vacanza Marino Vanto Spa VMA4R6393

  2. Back To Top    #2
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Veryifying plans

    The addition of cya does not move ph much. You can use the "effects of adding chemical section of the poolcalcultor.com to find out how much. For your pool, adding 88 ounces of cya to raise cya 30 ppm should lower your ph ~ 0.6 Are you certain you have not used any chemicals that have added cya to your pool?

    You really need to get an appropriate test kit since pool store results are unreliable (and often wrong on cya) and not available when you need them. See: http://www.troublefreepool.com/pool-...kit_comparison

    Ignore TDS, it is not a useful measurement.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  3. Back To Top    #3

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,082

    Re: Veryifying plans

    I'm probably going to start with 10 CYA to test how fast we lose it
    That won't work for you.

    You can certainly add a dosage of CYA to get to 10 ppm but you cannot test for it. The lowest measurable test value for CYA is 20 ppm.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4

    Join Date
    Mar 2012
    Location
    Lewisville, Texas
    Posts
    71

    Re: Veryifying plans

    Good to know I guess I have to do 20 just for a test than..wish the tests were more precise. I thought the kits you could buy were similar to the ones the pool stores use? One of the kit is a Leslies kit I thought..
    Lewisville, Texas 22,000 Gallon IG Plaster Chlorine FNS Plus Vertical Grid D.E. Filter 60 sq. ft. 150 GPM Push/Pull Valve Hayward Ecostar SP3400VSP Baracuda Zodiac G3 Cleaner

    Caldera Vacanza Marino Vanto Spa VMA4R6393

  5. Back To Top    #5
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Veryifying plans

    Occasionally some leslies carry the taylor K-2005, but that does not have the most important FAS-DPD chlorine test (not to be confused with the DPD chlorine test). Only the Taylor K-2006 and the tf-100 have that test. It is rare/unlikely that any leslies will carry the K-2006 locally. Many of us have gotten the tf-100 since that is the best value
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  6. Back To Top    #6

    In the Industry

    Donldson's Avatar
    Join Date
    Jun 2009
    Location
    NW Ohio
    Posts
    2,637

    Re: Veryifying plans

    Quote Originally Posted by Raiken3712
    Good to know I guess I have to do 20 just for a test than..wish the tests were more precise. I thought the kits you could buy were similar to the ones the pool stores use?
    Despite what the pool store would have you believe, their testing is as accurate or less accurate than the ones we use. They may give you a sheet showing a CYA of 10, or 12, 157, but it is only to make people believe their testing is better than what can be done at home. CYA can only be accurately measured between 20-100. To add to my rant, when they say your FC is 2.39 (for example), it is also fake. Unless they are using the FAS-DPD test and using a 500 ml sample they can not test to a 0.01 ppm precision. It doesn't matter if their super wiz-bang computer has lasers attached to it's tester, they are not as precise as they like to pretend they are.

    EDIT: I meant to say CYA can be measured between 20-100 in increments of 10. That is as accurate of any reasonably priced CYA test I know. Since most pools should be between 30-80 this is an acceptable range.
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath - HIGHLY Recommended Test Kits

  7. Back To Top    #7

    Join Date
    Mar 2012
    Location
    Lewisville, Texas
    Posts
    71

    Re: Veryifying plans

    Well they use a test kit that looks much like the FAS-DPD...of course I don't know what kind it is so it might not be as good. CYA can't be measured more precisely? 30-100? That means the measurement for it isn't even precise with a good kit. Hmm

    I'm not sure what size the bottles used for the samples are so I have no clue of their sample size...its a small bottle. I'd say maybe a pint but don't know. 4 pints to a quart 4 quarts to a gallon...that could be about right.
    Lewisville, Texas 22,000 Gallon IG Plaster Chlorine FNS Plus Vertical Grid D.E. Filter 60 sq. ft. 150 GPM Push/Pull Valve Hayward Ecostar SP3400VSP Baracuda Zodiac G3 Cleaner

    Caldera Vacanza Marino Vanto Spa VMA4R6393

  8. Back To Top    #8
    techguy's Avatar
    Join Date
    Jul 2010
    Location
    Antelope, CA
    Posts
    2,687

    Re: Veryifying plans

    Are they using a powder to run the FC testing? Or just drops?
    -- Guy --
    10K gallons in 21' Round 52 inch wall Aqualeader AG, Hayward Power Flow LX 1.5 HP pump motor, Hayward Perflex EC50AC DE filter w/Cellulose, Wide mouth skimmer, 2013 new Diver Dan (craigslist) to replace the faded old Hayward AquaBug. TF-100

  9. Back To Top    #9
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Veryifying plans

    The cya test that comes with the tf-100 can measure down to 20 ppm. I think the taylor K-2006 only measures down to 30 ppm.

    The FAS-DPD test is a "count drops until the solution turns clear" method.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  10. Back To Top    #10

    In the Industry

    Donldson's Avatar
    Join Date
    Jun 2009
    Location
    NW Ohio
    Posts
    2,637

    Re: Veryifying plans

    Quote Originally Posted by Raiken3712
    I'm not sure what size the bottles used for the samples are so I have no clue of their sample size...its a small bottle. I'd say maybe a pint but don't know. 4 pints to a quart 4 quarts to a gallon...that could be about right.
    I'm sorry, I didn't make it clear I was joking. To get a 0.01 ppm FC precision with an FAS-DPD test they would need half a liter of water, a teaspoon or two of powder, and several hundred drops of reagent. All of this would cost several dollars per test and give completely useless precision. Rarely do you need more than 0.5 ppm precision. Very rarely you could use the 0.2 ppm precision. You would never need 0.01 ppm precision.

    Anyway I doubt they are using an FAS-DPD test, most likely a DPD "match the shade of pink" test, which isn't much more useful than the yellow block test in a cheap test kit. But either way I can guarantee they are not doing a test that is actually capable of measuring to 0.01 ppm FC.
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath - HIGHLY Recommended Test Kits

Posting Permissions

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