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Thread: help double check numbers

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    help double check numbers

    Here are the most recent test results:
    FC 2.5, CC 0, pH 7.7, TA 70, CH 400, CYA 40, temp 81

    2 months ago, some of the numbers were:
    TA 100, CH 360, CYA 60

    Goals according to pool calculator:
    FC 3-7, pH 7.5-7.8, TA 70-90, CH 250-350, CYA 30-50

    Since taking over pool maintenance, all I have used were bleach and MA.
    I've noticed that for the summer, I have to add much more MA. pH increases avg 0.1/day if not more.
    TA was 120 at one point. The pool has a spa spill over. I've redirected returns not to point towards the surface of water anymore to decrease aeration. I've never had to add any baking soda.

    Any red flags with these numbers, trend? I need some reassurance.
    In my case, is it reasonable to get some trichlor since it'll take care of CYA, pH and FC? I saw some trichlor on clearance. It seems to be useful to have on hand for use during vacation as well.

    TIA.
    Irregularly shaped IG pool with aggregates of squares and rectangles, spa overflows to pool
    21K gallon, Pebble tec, 450 sq ft, 125 GPM cartridge filter, 1hp pump, 1.5hp booster pump, Jandy heater,
    2 skimmers, 2 main drains, Hayward Navigator automatic vacuum connected to one of the skimmers

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    benavidescj's Avatar
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    Re: help double check numbers

    Aside from your FC being slightly low, should be between 3 and 5 ppm, everything looks good. I also have rising pH but is related to having a SWG. Is the pool new? On new pools you will see rising pH for the first few months. In my experience redirecting the jets off the surface has little effect on rising pH, but pointing them horizontally is better for circulation anyways. One of experts will have to answer your question about trichlor as I do not use it and have no experience with it.
    Carlos
    Pool: 28,000 gallons IG; IC 40 SWG; Pentair 120 gpm cartridge filter; Marble finish; Pentair Wisperflow 1.5 hp; Polaris 360
    Spa: 350 gallon; Bromine
    How to shock your pool

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    JasonLion's Avatar
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    Re: help double check numbers

    Your levels are all fine. There is no need to adjust anything other than raising the FC level as benavidescj suggested (which you generally need to do daily anyway).

    You should let the PH drift around between 7.5 and 7.8 and only adjust it when it hits the edge of that range.

    Your CH level is a little high, but it isn't off by enough that you need to do anything about it.

    Your CYA level is fine. Near the start of the season you want to raise it to 50, and it will then drift down slowly over the course of the season. So having it be 40 in August is just fine.

    You can let TA come down to 60, which should help reduce the PH increase a little. If that doesn't take care of it you can try adding borates to the pool, which will further slow the PH drift.
    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

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    Re: help double check numbers

    Thank you for your replies.

    Your CH level is a little high, but it isn't off by enough that you need to do anything about it.
    How high should CH be before I need to drain the pool?

    Your CYA level is fine. Near the start of the season you want to raise it to 50, and it will then drift down slowly over the course of the season. So having it be 40 in August is just fine.
    Does CYA get consumed less during the winter? Is 30 ok for the winter for S. Ca? How often do you test CYA?

    You can let TA come down to 60, which should help reduce the PH increase a little. If that doesn't take care of it you can try adding borates to the pool, which will further slow the PH drift.[/quote]
    What happens to pH when TA is too high or too low? Why is a lower than normal range TA recommended (range in the calculator is 70-90). Please help me understand the reason behind it.

    Thanks again!
    Irregularly shaped IG pool with aggregates of squares and rectangles, spa overflows to pool
    21K gallon, Pebble tec, 450 sq ft, 125 GPM cartridge filter, 1hp pump, 1.5hp booster pump, Jandy heater,
    2 skimmers, 2 main drains, Hayward Navigator automatic vacuum connected to one of the skimmers

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    Richard320's Avatar
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    Re: help double check numbers

    Worry about CH when it gets into 4 digits. Or when you plug your numbers into Pool Calculator and can't get the CSI down into the safe zone.

    It's just a fact of life here in California. We have hard water.

    When it does get bad, you're probably close enough to get simicrintz to drive up and run the reverse osmosis filter on your pool.
    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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    benavidescj's Avatar
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    Re: help double check numbers

    When TA is too high your pH will tend to climb at a faster rate than if it is in the recommended range. If TA is too low your pH will tend to drift (not be stable) because TA is a buffer. The reason you can let the TA go lower than recommended is in situations where the pH tends to climb. As you lower the TA you will get to a point were the pH will want to start drifting down. Having a low TA along with Borates (another buffer) will keep your pH from climbing and keep the pH from drifting. It is a balancing act.

    One of the experts should be along to answer your question about CYA consumption.
    Carlos
    Pool: 28,000 gallons IG; IC 40 SWG; Pentair 120 gpm cartridge filter; Marble finish; Pentair Wisperflow 1.5 hp; Polaris 360
    Spa: 350 gallon; Bromine
    How to shock your pool

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    frustratedpoolmom's Avatar
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    Re: help double check numbers

    CYA doesn't get consumed over winter. I guess I'm not understanding the question? Testing CYA monthly or so is usually fine.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

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    duraleigh's Avatar
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    Re: help double check numbers

    Does CYA get consumed less during the winter? Is 30 ok for the winter for S. Ca? How often do you test CYA?
    CYA is only consumed by splashout but there is obviously less of that in the winter so. Yes.

    I would suggest leaving it at wherever you end up at the end of the swim season.......30 is probably adequate.

    I probably test mine 4-6 times annually. Someone newer to pools may test 6-8 times or a little more. Some on the forum really like to keep it tightly under control and will test weekly.....that's fine, too.

    Test your fill water for CH. You can probably manage it carefully with drain and refill to keep it under 400. If not, you will have to manage it and pH and TA more carefully.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: help double check numbers

    Quote Originally Posted by irvinenewbie
    Does CYA get consumed less during the winter? Is 30 ok for the winter for S. Ca? How often do you test CYA?
    You might find a larger loss of CYA in winter here in so Cal. Almost all our rain occurs in Dec-Feb, so it's the only time you'd expect the pool to overflow. (Not attempting to disagree with the Moderators. We dont cover our pools and mine overflows quite a bit in winter)

    Quote Originally Posted by irvinenewbie
    What happens to pH when TA is too high or too low? Why is a lower than normal range TA recommended (range in the calculator is 70-90). Please help me understand the reason behind it
    Low TA will tend to push Ph down, High TA will tend to push PH up. Depending on your pool and source of chlorine there is possibly an ideal TA number that will minimize the drift. Your pool has a bit of aeration (PH up) and you're using bleach (Ph up) so by lowering TA down a bit you can hopefully offset those upward PH tendencies.

    There's a limit to how much you want to use TA to modify PH drift. There's a relationship with PH, TA and CH - low numbers and your water will leach the calcium from your plaster. High numbers can cause calcium scaling.

    If you play around with the PH TA and CH numbers in the pool calculator you'll get a sense of how it moves that CSI number around.

    Adding borates can further help buffer your PH. You are replacing Carbonic Alkalinity with Boranic Alkalinity - both components of your Total Alkalinity (TA). The borates are a stronger buffer.

    Quote Originally Posted by irvinenewbie
    How high should CH be before I need to drain the pool?
    I tested my fill water last month at 450. My pool's CH is at 1100
    Depending on your fill water this is a beast you'll never keep ideal in So. Cal. If your pool overflows in winter, this will help offset your CH's tendency to creep up in the summer.

    Testing Frequency - If you are nervous try monthly on all those slow moving numbers (CYA, CH, TA) for the next year or so. That'll give you a sense of how they move and you can test less frequently.

    If you let that TA number come down to 60 and you're still adding a lot of acid keep an eye on it. That CSI number will start to change quickly with TA below 50. That said, even if you let your CSI sit at -0.8 for a month your plaster isn't going to crumble.
    16K Gal Plaster | Compupool SWG | Intelliflow VF | TF-100

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    Re: help double check numbers

    Sorry about my absence for the past few days. Thank you very much for all your help. I have a better understanding now.
    Irregularly shaped IG pool with aggregates of squares and rectangles, spa overflows to pool
    21K gallon, Pebble tec, 450 sq ft, 125 GPM cartridge filter, 1hp pump, 1.5hp booster pump, Jandy heater,
    2 skimmers, 2 main drains, Hayward Navigator automatic vacuum connected to one of the skimmers

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