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Thread: My CYA went to 0...

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    My CYA went to 0...

    I purchased my house at the beginning of the summer last year and my CYA was around 220. I did several partial drains and got it down to 50. Since it was at 50 last summer and i only use liquid bleach as my chlorine I have assumed it was still 50. I have only tested my FC a few times this year and have been adding the same amount of chlorine every night that I did last year and it has been staying crystal clear. This weekend I noticed it was a bit dull so I tested FC and it was 0 so I began a SLAM based on CYA of 50. I got my FC up to 20 and it was going away really fast during the bright hot day (95 - 99 degree in full sun). After the first night of SLAM i did a OCLT and had only lost 2ppm FC with no CC. After the second night of SLAM I did a OCLT and lost 0 FC. This did not seem right since I use so much FC during the day... I did a CYA test and it is now 0. I tested it again and it is indeed 0.

    I currently have 2 socks full of CYA pellets floating in front of the skimmers...

    This seems really strange to me. From what I have researched and read this seems really rare. I'm going to be testing very closely to see what happens. It may be time to use up these leftover chlorine pucks since I need CYA.
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Re: My CYA went to 0...

    What did your pool look like when you opened it this year? Any odd color or odor?
    Bob - Palm Beach by San Juan Pools. approx 5000 gals., Pentair 320 cartridge filter (all new guts installed by me), Goldline SWG, 'New to me' Kreepy Krauly Sand Shark, Intermec 104 Timer Test kit: TF-100 w/Speed Stir

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    Re: My CYA went to 0...

    Quote Originally Posted by pabeader View Post
    What did your pool look like when you opened it this year? Any odd color or odor?
    I never closed it. No strange odor or color... it has been nice and clear until Saturday when it started looking a tiny bit dull.
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Re: My CYA went to 0...

    Are you testing your CYA while FC is around 20? That will affect the results.
    20k gal. IG plaster w/spa. 2 HP Aqua-Flo "A" pump, Hayward DE6020 filter. "The Pool Cleaner".

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    Re: My CYA went to 0...

    Wow. I'm learning all kinds of new stuff today.
    Bob - Palm Beach by San Juan Pools. approx 5000 gals., Pentair 320 cartridge filter (all new guts installed by me), Goldline SWG, 'New to me' Kreepy Krauly Sand Shark, Intermec 104 Timer Test kit: TF-100 w/Speed Stir

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    Re: My CYA went to 0...

    Quote Originally Posted by sbcpool View Post
    Are you testing your CYA while FC is around 20? That will affect the results.
    No, FC had come down to 9 from 20 when I performed the CYA tests.
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Re: My CYA went to 0...

    I test my CYA monthly...food for thought!
    39YO 13K gallon former SWAMP/MONEY PIT, concrete bottom/Fiberglass Walls, Ecotech VS pump, Hayward Sand Filter, Dolphin DX5 Plus, Loop-Loc safety cover and YES, I have a TFT-100 test kit!

    Shock Level and Maintain - CL/CYA Chart

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    Re: My CYA went to 0...

    How often do you backwash that sand filter?
    16000 Gallon Plaster pool, Tagleus 2 TA100 Sand Filter filled with Zeobrite media, 3/4 HP Sta-Rite pump, Dolphin Deluxe 4 Robot, BBB method, Taylor K2006 Test kit. Nothing to brag about here. Lifelong Student of Life. "If you know everything, you fail to learn anything." --not sure who said that--

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    Re: My CYA went to 0...

    I backwash whenever my gauge shows the psi raises to the point my gauge shows. On my gauge it has a 10 psi range knob that I set when I backwash. Once it raises 10 psi since last backwash I do it again. My attn is usually drawn to it when the flow from pool inlets start to seem low.

    With that said I do it roughly every 2 months.
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Divin Dave's Avatar
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    Re: My CYA went to 0...

    Hi Chloe,
    Backwashing the filter of course takes a bit of water from the pool. Along with the water goes a bit of CYA every time.

    Also, I know you folks over in Mississippi also had a 10 Tons of rain this spring like we did here in East Texas. If your pool overflowed or you had to empty water to prevent it from overflowing, then along with that water went the CYA. I'm sure thats what's happened to it.

    hope this helps solve the mystery!




    Quote Originally Posted by Cloey123 View Post
    I purchased my house at the beginning of the summer last year and my CYA was around 220. I did several partial drains and got it down to 50. Since it was at 50 last summer and i only use liquid bleach as my chlorine I have assumed it was still 50. I have only tested my FC a few times this year and have been adding the same amount of chlorine every night that I did last year and it has been staying crystal clear. This weekend I noticed it was a bit dull so I tested FC and it was 0 so I began a SLAM based on CYA of 50. I got my FC up to 20 and it was going away really fast during the bright hot day (95 - 99 degree in full sun). After the first night of SLAM i did a OCLT and had only lost 2ppm FC with no CC. After the second night of SLAM I did a OCLT and lost 0 FC. This did not seem right since I use so much FC during the day... I did a CYA test and it is now 0. I tested it again and it is indeed 0.

    I currently have 2 socks full of CYA pellets floating in front of the skimmers...

    This seems really strange to me. From what I have researched and read this seems really rare. I'm going to be testing very closely to see what happens. It may be time to use up these leftover chlorine pucks since I need CYA.
    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.
    www.tftestkits.net Experience- it's what's learned just after you needed it most !!

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    Re: My CYA went to 0...

    Quote Originally Posted by Divin Dave View Post
    Hi Chloe,
    Backwashing the filter of course takes a bit of water from the pool. Along with the water goes a bit of CYA every time.

    Also, I know you folks over in Mississippi also had a 10 Tons of rain this spring like we did here in East Texas. If your pool overflowed or you had to empty water to prevent it from overflowing, then along with that water went the CYA. I'm sure thats what's happened to it.

    hope this helps solve the mystery!
    We did get a lot of rain earlier in the year. I never got enough rain to overflow but I did have to drain an inch or two off about 3 times... but with this in mind I would have to replace 50% of the pool to reduce it from 50 to 25. I do not see how it is possible for this to have caused my cya to go from 50 to 0 (assuming 0 - it is clear and black dot is highly visible when tube is full).
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Re: My CYA went to 0...

    If I'm not mistaken, you can lose 2 ppm of CYA per month due to oxidation and other reasons. I saw this in a post by chemgeek...so let's say you lost 2 ppm x 12 = 24 ppm, add to this the dilutional effects caused by rain, it seems entirely possible to have zero CYA over the course of 1 year.
    39YO 13K gallon former SWAMP/MONEY PIT, concrete bottom/Fiberglass Walls, Ecotech VS pump, Hayward Sand Filter, Dolphin DX5 Plus, Loop-Loc safety cover and YES, I have a TFT-100 test kit!

    Shock Level and Maintain - CL/CYA Chart

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    Re: My CYA went to 0...

    Quote Originally Posted by jaduck View Post
    If I'm not mistaken, you can lose 2 ppm of CYA per month due to oxidation and other reasons. I saw this in a post by chemgeek...so let's say you lost 2 ppm x 12 = 24 ppm, add to this the dilutional effects caused by rain, it seems entirely possible to have zero CYA over the course of 1 year.
    Ahh, that I had never read. This could indeed explain it. Needless to say I will be checking it more often.
    ____________________________________________________________ ___________
    15,000 gallon in ground pool with liner, Purex Triton Tagelus sand filter, Pentair Superflo 1HP.... Clinton, MS.

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    Re: My CYA went to 0...

    I too am having CYA issues this year and this thread contains some great information including a post by Chem Geek I don't CYA what I'm doing wrong. - Page 2
    5900 G Fiberglass IG pool (circa 1990), SWG Hayward Aqua Rite GoldLine (2013), IntelliFlo Variable Speed Pump (2013), Hayward Pro Sand Filter (circa 1990), Well water (no iron or other metals fortunately), test with Taylor K2006C, Charleston, SC

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    Re: My CYA went to 0...

    I test CYA every two months, and when it has dropped by 10 that means it's time to take a vacation, so I can put some pucks in.
    10,500 gal IG, Topaz Pebble, auto-level
    Hayward DE filter, 2HP Ecostar VSP, ProLogic PS-4, GVA actuators
    Cal Pools Wave Force Plus (wall return jets plus 2 floor pop-ups), Venturi Skimmer
    Water sheer, 2 wok pots, bubbler stem on the baja step
    ColorLogic Mutlicolor LED lamp. Taylor 2006+speed stir

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    Re: My CYA went to 0...

    That 2-3 ppm CYA per month loss is with a covered pool and is from chlorine oxidation of CYA. It may be higher in a pool exposed to a lot of sunlight (from some oxidation of CYA by hydroxyl radicals formed from breakdown of chlorine from sunlight). So while it is still true that CYA degradation is too slow to be able to use only Trichlor pucks as an exclusive source of chlorine, it is nevertheless a factor to consider in maintaining a CYA level over many months. Testing CYA twice a season for a summer season makes sense -- once upon opening and again mid-season (optionally again at end of season). In a hot spa, the CYA loss is around 5 ppm per month which is why in the Dichlor-then-bleach method one uses Dichlor about once a month to maintain the CYA level.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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    Re: My CYA went to 0...

    I test my CYA a couple days after I backwash. After 2 or so back-washes, I can see a reduction. I also have a large sand filter that uses quite a bit of water at each backwash. My pool also receives at lot of full sun. I look at it as a blessing. No problem using the pucks when traveling.
    16000 Gallon Plaster pool, Tagleus 2 TA100 Sand Filter filled with Zeobrite media, 3/4 HP Sta-Rite pump, Dolphin Deluxe 4 Robot, BBB method, Taylor K2006 Test kit. Nothing to brag about here. Lifelong Student of Life. "If you know everything, you fail to learn anything." --not sure who said that--

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