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Thread: FC and TC Dropping Consistently

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    FC and TC Dropping Consistently

    Hello TFP...just tested my water. I keep getting pretty high CC numbers along with a bit of unbalanced pH and TA. I am in the process of raising the TA right now.

    FC 3.5
    CC 6.0
    pH 8.0 might be a little higher. Test sample was a little purple/red
    TA 80
    CH 260
    CYA 30

    What steps should I take to get some better results? My water is clear as well.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Texas Splash's Avatar
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    Re: High Combined Chlorine Numbers

    Don't raise your TA. Not needed at the moment. pH needs to come down to about 7.2 in preparation for a SLAM, and a higher TA won't help. Since your water is clear and you have CYA, I would recommend lowering the ph first to 7.2 and begin a SLAM. Watch and maintain your FC to "12" and keep it there. Watch it carefully for the first few hours as it may try to drop on your quickly with that high CC reading. Maintaining an FC of 12 is extremely important at the moment. Stay close to the SLAM page (link below) and let us know if anything odd happens during your SLAM. Good luck!
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
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  3. Back To Top    #3

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    Re: High Combined Chlorine Numbers

    I need to shock again? I used some shock, 10lbs or so, when I opened up this year.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Richard320's Avatar
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    Re: High Combined Chlorine Numbers

    6 CC?

    First question: Have you added any non-chlorine "shock" products ... green-to-clean, yellow-out, oxone, magic egg... anything at all that promises to clear your pool without chlorine? They can interfere with the CC test. If not, then you probably have the earliest rumblings of an algae battle. The solution for that we call a SLAM It's similar to a pool store shock, but it's not just a wild guess about how much chlorine to add, and it lasts long enough to actually kill all the algae so you're rid of it for good, not just a week or two.

    Now... TA of 80 is just fine. Don't raise it. You'll end up on a ridiculous see-saw where this week you add baking soda (Alkalinity up) and then the pH rises so you add acid (pH down) to lower it but it lowers the TA so you add baking soda....and so on and so on.
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: High Combined Chlorine Numbers

    I used Power Plus Shock when I opened. 10 pounds. The CC number has come down over the last couple days. I was at 11.8 at one point.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by MAndrews1 View Post
    I used Power Plus Shock when I opened. 10 pounds. The CC number has come down over the last couple days. I was at 11.8 at one point.

    Sent from my SM-G900T using Tapatalk
    Power Powder Plus From Leslies? That wouldn't do it.

    You need to SLAM That's like the pool store shock, but not just a one-time mega-dose. It's done to a controlled set of parameters for a sustained period of time. If the water is still clear, a day or two babysitting the pool every couple hours ought to do it.
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: High Combined Chlorine Numbers

    Yes from Leslie's. I will give the slam process a look. I came across this site after I put the shock in. I see the SLAM referenced quite often.

    It's finally raining now, so I might have to wait it out a bit.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by Richard320 View Post
    Power Powder Plus From Leslies? That wouldn't do it.

    You need to SLAM That's like the pool store shock, but not just a one-time mega-dose. It's done to a controlled set of parameters for a sustained period of time. If the water is still clear, a day or two babysitting the pool every couple hours ought to do it.
    I tested my pH again and it is coming down. Around 7.8 now v.s. 8+. I am curious....I do have very clear water in the pool but the CC reading is still there around 6.0. While I can't see any algae, can it still exist? I do have a stain that is all around the pool. I can't scrub it off, but when I try, I get a little cloudiness coming off the wall.
    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Richard320's Avatar
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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by MAndrews1 View Post
    I tested my pH again and it is coming down. Around 7.8 now v.s. 8+. I am curious....I do have very clear water in the pool but the CC reading is still there around 6.0. While I can't see any algae, can it still exist? I do have a stain that is all around the pool. I can't scrub it off, but when I try, I get a little cloudiness coming off the wall.
    CC doesn't have to be from algae. Anything organic that is in the process of being oxidized by the bleach can release CC. When's the last time you cleaned out the skimmer basket and the pump strainer and the filter? Same water, just not visible.

    Also behind the lights and inside and beneath ladders and steps. Check out the pictures
    Think I may have found my FC demand issue?
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by Richard320 View Post
    CC doesn't have to be from algae. Anything organic that is in the process of being oxidized by the bleach can release CC. When's the last time you cleaned out the skimmer basket and the pump strainer and the filter? Same water, just not visible.

    Also behind the lights and inside and beneath ladders and steps. Check out the pictures
    Think I may have found my FC demand issue?
    Just cleaned it out yesterday along with a backwash.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by Richard320 View Post

    Also behind the lights and inside and beneath ladders and steps. Check out the pictures
    Think I may have found my FC demand issue?
    I will be checking this. I have never removed the light in the time we've had the pool. Unfortunately I'll have to wait until tomorrow. As far as bleach goes ... any recommendations on brand, strenght, etc.?

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: High Combined Chlorine Numbers

    Quote Originally Posted by MAndrews1 View Post
    I will be checking this. I have never removed the light in the time we've had the pool. Unfortunately I'll have to wait until tomorrow. As far as bleach goes ... any recommendations on brand, strenght, etc.?

    Sent from my SM-G900T using Tapatalk
    Walmart has near about the best price in my area for 10% @$2.50/gal
    Don't buy anything from the laundry aisle, go to where the pool products/outdoor area is.
    30k in ground vinyl lined pool surrounded by decking in the woods.
    Hayward sand filter circa mid 80's
    If there is a way to do things less expensively and yield a superior product I am all ears

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    FC and TC Dropping Consistently

    Hello. I've tested my chlorine levels the last 3 days in a row and both numbers have been dropping. I have the chlorinator loaded with 3" pucks. I hope it's working correctly. Is this a case of the FC consuming CC, therefore lowering the FC (use) and CC (consumption) or could my chlorinator be broken? It's brand new.

    4 days of numbers are below. PH has been between 7.2 and 7.8

    FC Saturday to Tuesday: 3.5, 2.0, 2.0, 1.0
    CC Sunday to Tuesday: 6.0, 6.0, 3.0, 2.0

    Thanks

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: FC and TC Dropping Consistently

    Your post indicates you do not have a good grasp of the FC/CYHA relationship. read "The ABC's of Pool Water Chemistry" up in Pool School and ask lot's of questions. We'll all help get you on the right track.

    What are you using for a test kit?
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: FC and TC Dropping Consistently

    Quote Originally Posted by duraleigh View Post

    What are you using for a test kit?
    Taylor K-2006

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

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    Re: FC and TC Dropping Consistently

    That's a good kit. When you get a chance, post up your complete test results like this....

    FC -
    CC -
    TC -
    pH -
    TA -
    CH -
    CYA -
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: FC and TC Dropping Consistently

    Quote Originally Posted by duraleigh View Post
    That's a good kit. When you get a chance, post up your complete test results like this....

    FC -
    CC -
    TC -
    pH -
    TA -
    CH -
    CYA -
    Here is what I got.

    FC - 1.0
    CC - 3.0
    PH - 7.5
    TA - 70
    CH - 270
    CYA - I'd say less than 30. I can see the dot clearly when the test tube is completly full.

    15,500 Gallon - In-Ground - Gunite Pool - Kidney Shape / Hayward S220T Sand Filter / 3/4 HP Hayward Pump / K-2006 Test Kit / Chlorine 3" Pucks

  18. Back To Top    #18

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    Re: FC and TC Dropping Consistently

    As your 3" chlorinating pucks dissolve (slowly) they with emit some FC and gradually raise CYA, while at the same time lowering pH a little
    They really don't dissolve at a significant rate to chlorinate your pool

    With a CC reading of 3 - something is consuming the FC faster than the pucks can dissolve.
    You need to pick up some bleach, right now Walmart has 10% bleach in their pool/outdoor section for $2.50/gal
    30k in ground vinyl lined pool surrounded by decking in the woods.
    Hayward sand filter circa mid 80's
    If there is a way to do things less expensively and yield a superior product I am all ears

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    Re: FC and TC Dropping Consistently

    Your CYA is too low and your CC are way too high.

    The purpose of the CYA is protect the FC from being depleted by UV from the sun.
    We recommend a minimum of 30.

    also, CC is not actually consumption.
    CC is combined chloramines which is the by-product of FC that is destroyed fighting organics
    in the pool. Your CC should never be above .5

    FC is Free Chlorine. Its what's available to sanitize the pool.
    TC is Total Chlorine. Its the sum of FC+CC

    If your CC is 3. Then there is something in the water which is consuming the FC. Algae outbreak are invisible until its too late, but if you test often as we recommend in Pool School, you can catch it before it gets out of control and resolve it quickly and easily.

    If your test of CC is accurate, you are a candidate to SLAM your pool.
    Divin Dave,
    IG Vinyl, 15' x 30', 3 1/2' - 6' deep, Oval, ~15K gal, Intelliclor IC40, Intelliflo VS pump, Clean and Clear 420 Filter, auto-fill-disabled, Retrofit LED Color Light, Dolphin Nautilus Robot, TF100 Test Kit, Taylor K1766 Salt Test Kit, Tftestkit Pressure Gauge.
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    Re: FC and TC Dropping Consistently

    Is this a fresh fill with high CC water? Did you put any other random chemicals in it recently that could be causing the high CC?
    Jason, TFP Moderator
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