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Thread: New Member, First time testing, seeking help high CYA - drain, close??

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    swoopman's Avatar
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    New Member, First time testing, seeking help high CYA - drain, close??

    Hi there,

    Got my new TF-100 test kit and did my first test.

    Here are the results:
    FC: 26.5
    CC: 1
    pH: 7.4
    Calcium: 375
    TA: 130
    CYA: 100

    Obviously the CYA is way high from using pool store chemicals.

    The FC is also way high. I used a full scoop of R-0870 but this was my first time testing so it could be operator error.

    We don't want to drain the pool and add water to fix CYA. Is it possible to limp along with adjusted bleaching dosages for the rest of the season until the pool is drained for closing in the fall? After the winter we hopefully will have enough fresh water from rain, snow or spring fill to fix CYA.

    The pool was sparkling a few days ago but is now cloudy. I can post a pic or give more details about what we've done this season but I don't want to add a bunch of info if it's not needed.

    I've been reading the forum a lot over the last week. I've learned a lot (thanks!) but can only take in and retain so much at once. So you're help would be greatly appreciated! Where should I start?

    Thanks so much
    Last edited by swoopman; 07-29-2014 at 09:49 PM. Reason: change title
    TF-100 Test Kit
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    Polaris Automatic Pool Cleaner, PB4-60 3/4 HP pump

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    JasonLion's Avatar
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    Re: New Member, First time testing, seeking help - high FC, high CYA

    Welcome to TFP!

    The CYA test will read anything over 100 as 100, so your actual CYA level might be far higher. You should do the CYA test again, but this time mix equal amounts of pool water and tap water, do the test with that mixture, and then multiply the result by two. That is less precise, but it will tell you if you are really near 100, or much higher.
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    swoopman's Avatar
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    Re: New Member, First time testing, seeking help - high FC, high CYA

    Thanks for the welcome and the recommendation.

    We did the CYA test again following your directions. This time the result was 160 CYA. We did the test both indoors and out (with back to sun - we were reading the extended test kit directions as you responded). We added some water to the pool today - not that it will make a big difference in CYA but the pool needed it and I thought I'd mention it.

    We also redid the FC test after reading that thread and came out with about the same result - FC: 25.

    Where do we go from here with that CYA reading?

    Thanks,
    Jeff
    TF-100 Test Kit
    22,000 gallon, 20x40 kidney-shape IG plaster pool built in 1986
    Nautilus NS-36 DE filter, Hayward Self Prime Super Pump 1HP
    Polaris Automatic Pool Cleaner, PB4-60 3/4 HP pump

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    Re: New Member, First time testing, seeking help - high FC, high CYA

    I know you said you don't want to replace water now, but to keep FC up to recommended levels, you will be using a lot more bleach. It's a matter of which is more expensive jugs of bleach or water. You will need to test daily and add enough bleach to get it back up where it needs to be. After a couple of days you should be able to calculate your daily chlorine usage to see what's the most cost effective way of dealing with your cya problem.
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    Richard320's Avatar
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    Re: New Member, First time testing, seeking help - high FC, high CYA

    I did just what you propose when I took over because we were under water restrictions and draining would have probably gotten me a huge bill, a fine, and a restrictor installed on my meter at my expense. My CYA was even higher. I speak from experience.

    If you're not under water restrictions or on an iffy well, a partial drain and refill makes life much easier. The problem comes in when you maintain high enough FC for your CYA - in your case, a minimum FC of 12. You actually won't use any more bleach, but you'll have to keep it at a higher level. But the pH test is unreliable at FC above 10. So your pH will always be suspect, and pH is critical for skin and eye comfort as well as to prevent etching or scale.

    This thread shows what happens to the pH reagent at high FC. Even using chlorine neutralizer doesn't fix it.

    If the pool is clouding up, which could indicate an impending algae bloom, you're really in a bind. The amount of chlorine you'll need to get to SLAM level will break you. Water is actually relatively cheap under most conditions. It would be worthwhile to check the water company and see -- sometimes they will waive the tiered rates or the sewer fees for pool filling if you arrange it in advance.
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    swoopman's Avatar
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    Re: New Member, First time testing, seeking help high CYA, drain & close? [new title]

    Thanks for your input timerguy - it was helpful.

    Thanks Richard for your input. When we thought the CYA was 100 it seemed possible to consider spending the money on bleach to keep the pool open for just a couple more weeks. Last year the pool was closed in late August due to the huge amounts of tree debris so a couple of weeks of high bleach and then close a couple weeks early was the idea. I did a search on the forum for "too high CYA" and read through the threads. I see how helpful you have been to the many people who are in a similar situation. We really appreciate you responding to our thread despite having said something similar to so many people. It means a lot when you are new, still feeling your way around and fighting that mentality of "this is the way it's always been done and it worked before" regarding using pool store chemicals. So thanks!

    With the retest following Jason's directions revealing that the CYA is more around 150 and the info from Richard about what happens to the pH reagent at high FC we had to rethink our situation.

    Our current plan is to partially drain the pool, do some plaster patching since we have to drain anyway and then refill only to close level. Using the well is too much of a strain to do the refill. Our estimate is this will require water delivery costing $600. Taking the water down about 4-1/2' will expose all the areas in need of patching and leave the deep end completely filled. The property is on a hill. The house is at the top of the hill, the pool at a level about 20 - 30' below the house and then another 20 - 30' to the bottom of the hill. We will be able to discharge the drain water to the bottom of the hill without issue. With the deep end filled and the benefit of the hill we should be okay for a few days of plaster repair without an issue of floating of the pool.

    Obviously we will not be able to fully circulate the water after the fill since we are only filling to close level. Hopefully using a submersible pump with the discharge back into the pool can give us enough circulation to give us an idea of how much we have lowered CYA (and circulate bleach for closing). If we have an off-season like last year the pool will be filled with water by opening time. Whether through precipitation or a spring fill hopefully we will have changed out enough of the water to resolve the high CYA and can start next season using TFP. If not, we'll start the season with another drain and refill that should be significantly smaller.

    We'd welcome any feedback on the plan and/or any thoughts on something we may not have considered.

    Thanks!
    Last edited by swoopman; 07-29-2014 at 01:41 PM. Reason: update title
    TF-100 Test Kit
    22,000 gallon, 20x40 kidney-shape IG plaster pool built in 1986
    Nautilus NS-36 DE filter, Hayward Self Prime Super Pump 1HP
    Polaris Automatic Pool Cleaner, PB4-60 3/4 HP pump

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