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Thread: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

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    Question Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    A couple of readings from when I first got the house about a year ago:
    2/22/14 PH 8+, TA 80, CH 360, CYA 60, FC 0
    5/17/14 PH 8+, TA 70, CH 380, CYA 58, FC 0

    I have been putting only liquid chlorine and muriatic acid. I have been struggling with the high PH. I have a spa spillover which I understand is contributing to the high PH. My FC does not seem to hold very long even with a decent CYA level, and it is often zero when I check.

    Today, about a year later, I did a full reading and got:
    PH 8+, TA 90, CH 220, CYA 0, FC 0

    So what has happened to make my CYA disappear?

    FYI: Yesterday for some reason I decided to shock the pool (8k gallons) with 0.75 lb. of potassium monopersulfate. I regret it and will not be using it again. I will be sticking with chlorine. Could that powder oxidizer have affected my readings?

    I have a swarm of kids coming tomorrow for the weekend. How can I get the CYA up quickly for the chlorine to hold? The pool is in the hot SW FL sun.

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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    Ah, I think I know. I had a repair done and the spa was drained along with about eight inches of the pool. But I still find it strange that it is zero. Something like 10-30 would make more sense. I am assuming I just need to add some cyanuric acid?
    In-ground 12'x26' oblong, ~8,000 gallons, material is something like a concrete with pebble surface
    Pentair system: 1 HP pump, CC150 cartridge filter, UltraTemp 110 heat pump
    Spa with spillover

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    elwood58's Avatar
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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    Get CYA up to 50, and keep FC at 5 ppm in the meantime. I would up the Aflac to the recommended for CYa of 50 within a couple of days.
    19204 Gallon L Shape with a 10X10 2nd Step Baja Ledge. Intellichlor IC-40, IntellipH, Cartridge Filter, Pentair Heater/Chiller (Heat Pump). Tons of Deck with Deck Jets. Construction Complete 6/5/17.

    "If you don't measure it, you can't manage it!"

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    Divin Dave's Avatar
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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    My first question is who is testing the water? Are you testing with a good test kit or is someone else testing?

    You can definitely loose CYA over time. If you get enough rain, you will end up with overflow and that will dilute the CYA. I went from about 70 to less than 20 From Oct to March. We had a good bit of rain this year and there was a lot of overlfow from my pool.

    CYA can also break down over a long period of time given the right conditions. If you were to check for ammonia, then that would indicate CYA breakdown.

    Just add some CYA. Even though it takes a while to register on the test, it does react with the chlorine fairly quickly. Then maintain your FC relative to the CYA target you aimed for and you will be fine.

    If you have a recommended test kit, I would say check for CC and also do an Overnight CHlorine Loss Test just to make sure something didnt start growing while your FC was zero.

    Also a FYI. It is safe for anyone to swim with FC all the way up to the SLAM level.
    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: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    I have a swarm of kids coming tomorrow for the weekend.
    Importantly, what does your water look like?
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    What is Aflac? I am familiar with many terms but not that one.

    I have been doing the testing myself using the K-2006 kit. I usually only do the FC and PH tests. The others once every few months. We do have heavy rainfall season here but I don't recall ever experiencing overflow. I guess the water is evaporating as well, especially from the hot spa. I don't think I can do the CC test since it will pick up the potassium monopersulfate I just put in and I don't have the special neutralizing reagent. The overnight test is a good idea.
    In-ground 12'x26' oblong, ~8,000 gallons, material is something like a concrete with pebble surface
    Pentair system: 1 HP pump, CC150 cartridge filter, UltraTemp 110 heat pump
    Spa with spillover

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    Mod Squad pooldv's Avatar
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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    My cya drops quite a bit over the year. Especially when it is rainy. Couple that with draining the spa and isn't that surprising. Yes, just add more. I have to add every year.
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    Richard320's Avatar
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    Re: Zero CYA, Zero FC, High PH... visitors coming tomorrow... what to do?

    Your situation is one of the rare ones where I would suggest using dichlor "shock powder." There are three varieties of powdered chlorine sold as "shock," so do read the label. Not knowing the size of your pool, I can't tell you how much each one pound bag will affect things, but pool math can. Plug your volume in, and your current readings, and then scroll down to effects of adding chemicals. It will tell you how much each pound will change FC, CYA, and pH.
    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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