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Thread: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates too.

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    Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates too.

    Long story - 23K gallon concrete pool. DE. Nature2.

    We had this new pool built 6 years. For some personal reasons, I couldn’t get around to get serious about the maintenance. So, I would add 2lb bag of chlorine every other week, kept a few tablet packs in a floater, and was running Nature 2 mineral sanitizer.

    The pool is at the lower end of the development so there was a significant water runoff in the 1st year. Also, in a 2nd year. After that we improved the water drainage and not much is getting into the pool from the lawn.

    I am afraid that during the first two years I might have gotten a lot of organic junk into my pool.

    Last year, I finally started to see some algae. Easily brushed off. Hit it with 2 bags of Aqua Chem SuperBlue – all gone. I started getting worried when my in-law told me that after he shocks the pool, he can’t swim, and I told him that I don’t have this problem. Even after adding 2 lb of chlorine bag, I get not much Chlorine reading.

    Finally, this year, I decided to get serious and started with testing on my own (TFT-100) and then taking to pool store. The results were very close. I will show range of two numbers as I am always a bit off.

    Monday – 3rd day after pool was open.
    In the morning – I took the water to store.
    FAC - 0 - 0.5 (likely 0)
    TC - 0 - 0.5 (likely 0)
    CH – 200
    CYA - 0 (yes 0)
    TA – 80 - 100
    PH – 7.6 – 7.8

    Pool Store:
    TDS = 600 (ok)
    Pho – 0

    When I explained that I had no chlorine reading last year – they checked for Nitrates (with a strip) and told me – they are off the charts – 150? Told me to drain water and not waste money on balancing.
    Monday night -
    I added 4 lbs of Stabilizer to the skimmer (removed the plastic baskets).
    poured 3 x 121 OZ 8.3% Bleach.
    In the morning – got no reading of Chlorine.

    Tue –
    Nitrates Strips arrived. They have 50 max. So, I used ¼ pool ¾ tap water, got reading of 10, so x4 = 40. Still very high.
    CYA I had measured at 20-25.
    In the evening – Put 2 bags of Sodium Dichloro-s-triazinetrione 63.05% (Chlorine 39%). 30 minutes - No change in Chlorine. Added another 3 bags so now it was 5 lbs total.

    Wed
    In the morning – still practically no chlorine. Not even Total Chlorine. I got maybe 1. Took to pool store
    Here are the latest readings:
    FAC - 0 - 0.5
    TC - 1.5 – 2
    CH – 200 – 300
    CYA - 40-45
    TA – 100 – 110
    PH – 7.4 – 7.6

    Pool Store:
    TDS = 1000 (ok)
    Pho – 0

    The guy at Leslies encouraged me to replace at least ½ of the water. I said, I wanted to continue with chlorinating. He suggested to drop two bags of Oxidizer (potassioum perox….) 4% oxygen to release free chlorine. I did this Wed night.

    I also bought 8 gallons of liquid chlorine. I also have about 6 jugs of 8.25% Clorox (about 5.7 gal). I haven’t started putting it in.

    I didn’t put new Nature 2 cartridge yet.

    It is getting very nice and water now is around 77. The pool has a good, but not extreme, sun exposure during the day. The water looks very clear. I don’t see any algae.

    I have read that absence of CYA at the opening of the pool may suggest Ammonia. Also, nearly 0 TC / FC in the morning after suggests something consuming it at night – 2.8 gal of 8.25% bleach on Monday and 5lbs of chlorine on Tue and nothing to show for it.

    Can I start using pool? After all, we managed the whole last season without chlorine. Is it not safe? Should I replace ½ of the water to try to lower nitrates?

    Do I need to continue chlorinating until I get the FC to stay?

    I have read a few threads in the forum, and it seems like my case is not unique. I also noticed that with the help from the forum members people had solved their problems. As I am struggling though and really hoping to get some specific guidance here.

    Kids want to get into the water. Please help!
    built 2010. Concrete, 23,000 gallons, DE, Nature2 Mineral Cartridge G25

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    Mod Squad tim5055's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    What happened?? You were here in 2010 when you put the pool in and bought the best test kit there is.

    My first suggestion is to stop going to the pool store. Their only response it to sell you something. We say no to the Nature2 and Nitrates are meaningless. Nitrate numbers are just a way for the pool store to scare you into buying unnecessary stuff.

    Now is the time to make a decision, keep following the pool store and dropping lots of money there or follow our methods.

    If you want to follow our methods, you need to read the directions on SLAMing your pool in the How To section of Pool School and follow that procedure completely to the end.


    • CC is 0.5 or lower;
    • You pass an OCLT (ie overnight FC loss test shows a loss of 1.0 ppm or less);
    • The water is clear.


    When all three are true, you are done SLAMing and can allow the FC to drift down to normal levels.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    BoDarville's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    As Tim stated, you need to make a decision between following our methods or the pool store's methods. Trying to combine the two simply will not work.

    Secondly, you can ignore TDS, Phosphates, and Nitrates. In fact, the only parameters you need to focus on are these:
    1. FC - Free Chlorine - A sanitizer which keeps your pool water safe and free of germs. Chlorine must be constantly replenished. (level depends on CYA)
    2. PH - Acidity/Alkalinity - Needs to be kept in balance to prevent irritation and protect the pool equipment. (7.5 to 7.8)
    3. TA - Total Alkalinity - Appropriate levels help keep the pH in balance. High levels can cause pH to rise. (60 to 120, sometimes higher)
    4. CH - Calcium Hardness - Appropriate levels help prevent plaster damage. High levels can cause calcium scaling. (220 to 350, vinyl lower)
    5. CYA - Cyanuric Acid - Protects chlorine from sunlight and determines the required FC level. (outdoors 30 to 50, SWG 70 to 80, indoors 0 to 20)

    Thirdly, since you have CYA in the water along with no consistent CC spike, we can rule out ammonia.

    Bottom line: Something organic is living in your pool and that's what's causing the chlorine consumption. Clear water alone does not guarantee that your water is free from organics. Most algae infestations begin with clear water that can turn green overnight. It is possible that you could have algae behind a light niche and/or around or in a ladder.

    The cure: A SLAM - Shock Level And Maintain and testing with a proper test kit like your TF-100 (although if the reagents are over 2 years old, you may need fresh refills).
    Gold Supporter, TFP Lifetime Supporter, 26,680 gal Plaster IGP 3.5 - 10' depth / Attached Waterfall Spa, Manually Chlorinated, Triton Sand Filter, 1.5 HP * 1.1 SF = 1.65 SFHP 1-speed Pentair WhisperFlo WF-26 Pump, 400K BTU NG Teledyne Laars Series One Heater, Polaris 360, Test Kit Comparison, Chlorine/CYA Chart, SLAMing Your Pool, OCLT
    A good test kit is an investment, not an expense.

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Get rid of that ozone and use chlorine. Chlorine is much better at killing bacteria and keeping your family safe from heebie jeebies that can grow in the under chlorinated pool.
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Thank you for replies. This is what I was hoping to hear. So, I am going to start SLAM.

    So, from the charts CYA=40, I need FC at 16.
    From Pool Calc to get from 0 to 16 for my 23K, I would use 3 gallons of 12% liquid chlorine that I have.
    Is this right?

    Can you help with the process - I will start in the eve - Do I pour all 3 one after another? Anywhere in the pool?
    When do I re-test? 2 (or X) hrs?

    Say I get 1 FC and 4 CC (TC=5), do I ignore TC/CC and just focus on getting FC from 1 back to 16? Thus putting another 3 gallons X hrs after the initial 3 gallons?

    Is the only result I should care - FC getting to 16? Do I need to retest PH and CYA during this exercise?

    Thank you
    built 2010. Concrete, 23,000 gallons, DE, Nature2 Mineral Cartridge G25

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Quote Originally Posted by Igor View Post
    Thank you for replies. This is what I was hoping to hear. So, I am going to start SLAM.

    So, from the charts CYA=40, I need FC at 16.
    From Pool Calc to get from 0 to 16 for my 23K, I would use 3 gallons of 12% liquid chlorine that I have.
    Is this right?

    Can you help with the process - I will start in the eve - Do I pour all 3 one after another? Anywhere in the pool?
    When do I re-test? 2 (or X) hrs?

    Say I get 1 FC and 4 CC (TC=5), do I ignore TC/CC and just focus on getting FC from 1 back to 16? Thus putting another 3 gallons X hrs after the initial 3 gallons?

    Is the only result I should care - FC getting to 16? Do I need to retest PH and CYA during this exercise?

    Thank you
    You have most of it right. Did you read through the directions a couple of times? Pool School - SLAM - Shock Level And Maintain
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    BoDarville's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Focus on maintaining FC as close to the target level (16 ppm in your case) as possible until you meet the criteria of "done" for the SLAM. No need to test pH and CYA during the SLAM.
    Gold Supporter, TFP Lifetime Supporter, 26,680 gal Plaster IGP 3.5 - 10' depth / Attached Waterfall Spa, Manually Chlorinated, Triton Sand Filter, 1.5 HP * 1.1 SF = 1.65 SFHP 1-speed Pentair WhisperFlo WF-26 Pump, 400K BTU NG Teledyne Laars Series One Heater, Polaris 360, Test Kit Comparison, Chlorine/CYA Chart, SLAMing Your Pool, OCLT
    A good test kit is an investment, not an expense.

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    Isaac-1's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    That MPS Chlorine free shock the pool store sold you is likely confusing your test results now, MPS shows up as CC on the common pool tests (Taylor does offer a MPS compensation speciality test, but it is pricey). In my experience it can take MPS several days to stop showing up as CC depending on pool conditions.
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Thank you everyone. Great help!

    Update -
    Wed PM - did not add chemicals, just cleaned up / brushed. Pool water looks very nice. No leaves, a few pieces of derbies.

    Thu AM - TC / FC around 1 or so.

    Thu 9PM - based on CY 40, added 3 gal of liquid chlorine (target 16).
    Thu 11pm checked - finally saw FC in my pool! And it was high! FC =16 (32 drops to clear).

    Fri 7AM - FC is still there, but dropped to 7.5-8, CC is around 1-2.
    I plan to continue Friday 8PM with another round.

    Any comments? Corrections?

    Two questions -
    1. FC test: - how clear should the water after adding R871? I placed another tube with 100% pool water right next to the test tube. Should the test water become as clear, or somewhat clear - most of the pink gone? I usually see the latter.
    2. Am I having too long of a break between slamming sessions - 9PM Thu, and next one planned for 8PM today (Friday)?

    Thank you!
    built 2010. Concrete, 23,000 gallons, DE, Nature2 Mineral Cartridge G25

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    As I understand it you are supposed to keep the FC up at slam level constantly ...
    or you never get ahead of it .
    So keep it at 16 or above ...
    at your overnight loss rate you will have near zero by tonight
    Doug - Purchased 1/2016, 1995 house with 16x31 ft, ~23000 gallon Gunite pool w 11x7 spa, 3 Pentair VS pumps, a boost pump for polaris 3900 and a Badu® Jet super-sport swim jet pump, 1.5 hp blower, a CL460 Cartridge filter. TF-100 test kit. Aquapure SWG, iAqualink - Lots to learn. New Aquabright, Jandy LEDs, CMP LED Sheers.

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Often when there is a hint of pink in the FAS DPD test an extra drop or even 2 at times (0.5FC per drop on 10 ml sample) will make it 'clear' clear.

    As far as the SLAM goes the key is to maintain the SLAM at shock level as much as possible, ideally checking every hour or couple hours. Generally, the longer you maintain it, the quicker the process goes. But we all work etc so you do the best you can testing and adding as often as you can.
    11 000 gallons, IG, Fibreglass, Monarch Sand Filter, Davey Typhoon C100M 1HP pump, Davey Chloromatic Mc16CTO ESR SWG, Davey Pool Wall Climba Robot, Daisy Solar Cover,
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    Mod Squad tim5055's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    You are being advised correctly, anytime you test lower than 16 you should add to get back to that level.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Thank you for your comments.
    Friday
    7PM - FC held up since morning - FC=8, CC=0
    Added 1 3/4 gallons of liquid chlorine to get to 16 per formula.
    10PM, 11Pm - FC still around 16.

    Sat 7AM - FC dropped to 12. Added 3/4 gallon.
    Will keep checking.

    Really hoping this will be completed soon.
    built 2010. Concrete, 23,000 gallons, DE, Nature2 Mineral Cartridge G25

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    It's contradictory that you use more chlorine at night than in sun of day.....

    something is interesting
    Doug - Purchased 1/2016, 1995 house with 16x31 ft, ~23000 gallon Gunite pool w 11x7 spa, 3 Pentair VS pumps, a boost pump for polaris 3900 and a Badu® Jet super-sport swim jet pump, 1.5 hp blower, a CL460 Cartridge filter. TF-100 test kit. Aquapure SWG, iAqualink - Lots to learn. New Aquabright, Jandy LEDs, CMP LED Sheers.

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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    The water passed all the requirements listed in SLAM section.
    Kids are enjoying the pool.

    Thanks to everyone's for support and helpful comments!
    built 2010. Concrete, 23,000 gallons, DE, Nature2 Mineral Cartridge G25

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    Isaac-1's Avatar
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    Re: Please Help! TC and FC close to 0 after putting a lot in the Eve. High Nitrates t

    Glad you got it all cleared up, if you need any more help we will be around
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
    ~Remember TFP counts on your donations to keep this site ad free~

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