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Thread: Drained pool, now have 0 CYA and other questions...

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    Drained pool, now have 0 CYA and other questions...

    OK, so for the first time in history I have a below 100 cya level. The bad news is that I now have a 0 level according to the test results. I could still barely see the dot with the test tube completely full. My filter has been running for 3.5 hrs since refilling. At that time I also added 3 gal. of bleach. I tested my water just now, 3.5 hrs post fill and bleach addition. I have attached my results here as you can see on the pool calculator.

    I have questions based on these results.

    1. With my TA so high why doesn't the calculator tell me to add acid? I thought the preferred method was to knock down pH (with acid) and then aerate? Instead it is telling me to add pH increaser.

    2. If my cya is truly 0 do I have to go out and my stablizer or should I just used some stabilized trichlor etc for awhile? I am getting somewhat tired of buying stuff.

    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

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    Melt In The Sun's Avatar
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    Re: Drained pool, now have 0 CYA and other questions...

    Right now it's telling you to raise your pH because you said you wanted to raise your pH (now=7.2, goal=7.5). The pool calculator won't tell you to lower TA, but you already know how to do that Lower your pH to 7, then wait for it to go back up, repeat....

    Did you drain the pool completely? If you didn't, I'd retest that CYA in a little bit, because if you had over 100 you should still get a reading unless you replaced pretty much all the water. You can use trichlor to raise it if you want, but I think the cold turkey approach is probably best for you
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    maxepr1's Avatar
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    Re: Drained pool, now have 0 CYA and other questions...

    The second line in TA says it, "To lower TA reduce PH to 7.0-7.2 with acid and then aerate to increase PH, Note Adding soda ash will raise your PH". Also start adding CYA about half the amount called for and wait a week before testing and then just bump it up gradually. Stabilizer is what you want.
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    Re: Drained pool, now have 0 CYA and other questions...

    Quote Originally Posted by Melt In The Sun

    Did you drain the pool completely? If you didn't, I'd retest that CYA in a little bit,
    I introduced approx 20,000 gallons into my 9,800 (approx) pool over the course of several days. I did this while draining. So I think I essentially drained it. So, I guess my question now is....what to do first?

    I know that I should start knocking down my pH (and in turn my TA) but I am hesitant because I have had such a constant fight over the years with low pH, probably mainly due to the fact my well water has high pH and TA.

    This time when i filled up the pool and the last partial drain, I used city water for several thousand gallons because it has high pH and good TA. I'm also hesitant to go to the pool store and drop another $40 on stabilizer, when I just got rid of the cya (got levels below 100) yesterday for the first time in history.

    I think I am going to let things run another 24hrs and retest. I would like to see if my cya stays at 0.
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

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    Melt In The Sun's Avatar
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    Re: Drained pool, now have 0 CYA and other questions...

    Waiting to retest won't hurt anything; just make sure you keep some FC in there. You struggled in the past with low pH because you used trichlor, which drives down pH. Nix the trichlor, and you won't have that issue. Actually, with TA at 290 (worth retesting; that's really high) your pH will trend upward.

    How are you planning on chlorinating? I'm an SWG evangelist, and I think that would work well for you since you don't like having to lug jugs.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
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    maxepr1's Avatar
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    Re: Drained pool, now have 0 CYA and other questions...

    Walmart, has CYA for $15 for a 4lb bottle(HTH). That will get you close.
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    Re: Drained pool, now have 0 CYA and other questions...

    Quote Originally Posted by Melt In The Sun
    Actually, with TA at 290 (worth retesting; that's really high) your pH will trend upward.

    How are you planning on chlorinating? I'm an SWG evangelist, and I think that would work well for you since you don't like having to lug jugs.
    I test the TA twice and it tested 310 and 290. I wiped the tip of the r009 on the second test. I plan to just use bleach to chlorinate.
    Quote Originally Posted by maxepr1
    Walmart, has CYA for $15 for a 4lb bottle(HTH). That will get you close.
    I went to Walmart and picked up a 4lb bottle. Is the best method to just add to skimmer as instructions state?
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

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    maxepr1's Avatar
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    Re: Drained pool, now have 0 CYA and other questions...

    Wow, I thought 150 TA was high! You can pour a little at a time in the skimmer or do the sock method( filling a nylon sock and hanging it over the side)
    40'x19' IG Diamond Brite 29K 4' Waterfall/Dive Rock FNS60 DE Inteliflo VS 2hp Whisperflo pumps Aqualogic(P4) SWG TF100 Tester


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