Become a TFP Supporter Pool Math Forum Rules Pool School
Page 1 of 2 12 LastLast
Results 1 to 20 of 40

Thread: Numbers post partial drain and refill...

  1. Back To Top    #1
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74

    Numbers post partial drain and refill...



    Here are the results from my first complete test

    Temp. 72
    FC 7.5
    CC 0.5
    pH 7.7
    CYA 100 +
    TA 220
    CH 500

    the water is clear but I guess the prolonged "tablet" use has taken its toll..
    will get some distilled water and redo the CYA and CH to get a better picture..
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  2. Back To Top    #2

    Join Date
    Apr 2007
    Location
    Arizona
    Posts
    924
    Hi!

    Yes, the tablets and pool store shock create some problems with too high of a CYA.

    Your CC's are at .5 you really need to add chlorine at a high enough level to get rid of them. With your CYA you need to shock quite high.

    You should probably switch to liquid chlorine/bleach.

    Your TA is quite high, as well. Use Muriatic acid to bring it down. Add enough to bring your pH down to 7.0, which will also lower your TA. Then aerate to bring your pH back up and repeat with the muriatic acid.

    Consider draining some of your water to reduce your CYA.
    Buggs

    14,000 gallon, in ground, plaster, free form, play pool.
    Sta-Rite Max-E-Glass with a 1.5 hp Emerson motor
    WaterCo Micron High Rate sand filter S750 490 lb, 4883 sq ft - using ZeoBest
    In floor Polaris cleaning system
    Blue Diamond robot for those after storm days when I can't wait overnight for the in floor to clean it.

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879
    I wouldn't worry about CC at 0.5 or lower.

    The big issue is the CYA. The common CYA test will show anything above 100 as 100, so it could be quite high. Assuming that CYA is 150 you need to keep FC at 12 to keep algae away. It would be best to replace some water to try and get CYA below 100. Depending on your fill water, that might also help with your TA and CH, which are both high.
    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

  4. Back To Top    #4

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,045
    Saraiks,

    Your self-diagnosis is pretty good. The tabs have gotten your CYA up there where managing your water can be difficult. (although it seems like you're doing pretty well with clear pool water and an FC of 7.5)

    Draining some out and refilling may be a pain now but probably beneficial in a number of ways for the future. It should also help reduce your CH......not a bad idea, either. BTW, have you been using Calcium Hypochlorite either to shock or for some of your FC? That would explain the high CH.

    As Jason said, the CYA is your biggest issue.......requiring even more FC than you currently have. A 50% drain and refill may get all of your numbers back into a more manageable category.

    CC's of .5 or less are pretty common in many pools.....it's typically when they get to 1.0 or more that you need to pay attention.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  5. Back To Top    #5
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    I agree that a partial drain and refill is the first step. The gallons of clorox were the first item to be picked up yesterday.

    Question: Will diluting with distilled water give a good CYA reading ?
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  6. Back To Top    #6

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,045
    Question: Will diluting with distilled water give a good CYA reading ?
    Well, it certainly will add variance to a test that is already a little imprecise to begin with. So, if the CYA test can vary by 10-15% (that's just a guess) anyway, when you dilute by half, your error margin could be pretty big.

    I still think it's probably worth a try. It would at least give you a better indication of where you really are.

    Unless you already have it on hand, I see no real need to use distilled water. Your testing for turbidity (cloudiness) and good ole' tap water will probably give you the same result.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  7. Back To Top    #7
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    Thanks.. will take your advice and use good ol' tap water..
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  8. Back To Top    #8
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74

    Latest Results..

    Did another set of tests last night and here are the numbers. Found out the well known fact that FAS-DPD is the way to go.. the ordinary chlorine test was realy not giving the true picture...

    FC : 29 (FAS-DPD and yes I counted all of the **** 58 drops it took to do it....)
    CC : 0 (FAS-DPD)
    CYA 100 + (need to redo with a 1:1 dilution to get a ballpark number)
    pH : 7.6
    TA : 180 (was 210. Reduced pH to 7.2 with acid and aereated the pool to bring it back up as advised)
    CH : 500 (not retested)

    Question: Do you guys see any issues with running such a high FC even though the CYA for all practical purposes may be way up there ?
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  9. Back To Top    #9
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879
    High FC is needed when CYA is high. You have FC at shock level for a CYA of 130. That isn't going to hurt anything, but there is no need to keep it that high. I would let it drift down a little, say to 20, while you figure out what your CYA level really is.

    I suggest doing another round of acid and aeration to bring the TA down another step.
    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

  10. Back To Top    #10
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    I finally managed to do a CYA test with a 1:2 dilution. The result was a CYA of 70. Which means my actual CYA is close to 200. This explain a lot of things though. The FC level is very high because hardly any was lost due to the high CYA. The previous owners just had tablets in the skimmer all the time which kept it way up there. They did occasionally shock it with a Calcium based pool shock from Leslies which raised the CH to the high level it is.

    I will go ahead and do another round of Acid and aeration as suggested to get the TA a bit lower. The partial drain and fill is next on the list after that.

    Question: Is there any chemical method of reducing the CYA ??
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  11. Back To Top    #11

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,045
    I think there's one available at pool stores. Reports have been it's effectiveness is pretty weak (you need a ton of it) and it's prohibitively expensive. I believe you will find a 50% drain and refill (followed by another 50% drain and refill) is your best bet to have manageable pool water.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  12. Back To Top    #12
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    A drain and refill is not an easy option for the way my pool is plumbed. There is no Vaccum to waste possible. I might be able to siphon off a little and will have to pump out the rest.
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  13. Back To Top    #13
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879
    Do you have an overflow drain? If so you can simply add water at the other end of the pool and let the overflow drain keep the level from going up too high.
    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

  14. Back To Top    #14
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    I think I do have an overflow drain as I saw a small(3/8 ?) pipe hole sitting above the water lie. I was thinking of more like jerry rigging a hose to one of the jets and out to the kerb...!
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  15. Back To Top    #15
    divnkd101's Avatar
    Join Date
    Mar 2007
    Location
    Pearland, TX (Houston Suburb)
    Posts
    587
    Also check around your pump. You may have a regular water spiggot (attached to pool plumbing) to attach that hose to. I do have an overflow in my pool but when heavy rains come, I tend to open the spiggot as well and drain to the curb. Good luck.
    MIKE

    21K Inground Custom w/ Spa (Gunite/Plaster), SWCG, Hayward Northstar, Polaris 280, Hayward Color Logics, Jandy PS-8

  16. Back To Top    #16
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    I did find a spigot right next to the filter which is primarily used to drain the filter of all water before opening it up for cleaning. This has been attached to a plastic pipe with a flex connect fitting. This pipe drains directly to the kerb. I used it to drain the pool of about 3 inches of water. The Butterfly Valve in my skimmer is not working properly because as soon as the water level dropped below the weir door it started sucking in Air evethough the butterfly valve was fully closed. Assuming an avarage depth of 4 feet that is about 1/16th of the water. I intend to repeat this process again for the next few days to see if I can further lower the numbers into manageable range.
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  17. Back To Top    #17
    sammm's Avatar
    Join Date
    May 2007
    Location
    North Richland Hills, TX
    Posts
    257
    Quote Originally Posted by saraiks
    I used it to drain the pool of about 3 inches of water.
    I went thru the high CYA issue when we bought our house a little over a year ago. If your CYA is at 100 (or wherever), you will have to drain 1/2 of your water and refill with fresh water to cut that number in half. If it's 150, draining 1/2 the pool will drop it to 75. Painful, I know.
    WetEdge Satin Matrix, 16K gallon, Pentair NSP-60 DE filter, Pac Fab Challenger, 2HP pump, BBB, Polaris 360

  18. Back To Top    #18
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    Here are the numbers after two drain and refill's of bout 3" of water each..
    Temp. 72
    FC 18
    CC 0
    pH 7.6
    CYA 180 (1:1 dilution)
    TA 180
    CH 500
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

  19. Back To Top    #19

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,045
    If you're looking for comments, I think you're gonna' have to do a major drain (50%) on your pool to get your CYA manageable. You may, in fact have to do it twice. I know it's a PITA, but your life will be much simpler.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  20. Back To Top    #20
    saraiks's Avatar
    Join Date
    Jul 2007
    Location
    Fremont, CA
    Posts
    74
    A major drain is a PITA with the setup I have. I was planning to do a partial drain and fill of about 5% to 10% everyday for the next few weeks and see if that works. If not I'll rent a sump pump from somewhere and go for the major PITA.

    But you are right about life being easier after the drain and I am looking forward to it..
    16,000 G in ground Gunnite (plastered) with attached Spa, Gemini 3 NG Heater, Sta-rite cartridge filter, Aquabot Mark V, TF test kit

Page 1 of 2 12 LastLast

Posting Permissions

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