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Thread: CYA dropped, WHAT?

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    esim13's Avatar
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    CYA dropped, WHAT?

    hey guys and gals,
    So I've been trying to keep pool at shock level these last few days as recommended on earlier post. It's been tough - I teach Kindergarten, it's the last few weeks of school, everything going on, sinus infection to boot - I'm exhausted. BUT - Today is Friday!! which has given me a few bits of energy and I'm ready to tackle the pool again.
    I tested today around 5:00, sun still out, pool half in shade. I plan on testing again tonight after dark and doing another overnight test. As for today, here's what I got
    FC 6
    CC 0
    pH 7.4
    TA 120
    CH 140
    CYA 30 (What?? I tested this Monday and it was 60!!)
    So what's with that? I ran out of CYA testing solution, ordered more, it came in today and I just tested with it. I did the test 4 times! I got 30 and close to it each time. Am I that insufficient in testing CYA? Could the original R-0013 have had problems? Is the new R-0013 that much better? Am I good to go with CYA at 30 when Monday it was 60?

    Does everything else look on target?
    Thanks!
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    Re: CYA dropped, WHAT?

    If you're confident of your original reading, the most common reason for CYA to drop is water replacement. Have your been backwashing your sand filter? Also an autofill system can mask a leak. As it keeps topping off the pool, the dilution will result in a lower CYA number.
    32x16 ft Grecian rectangular vinyl pool 8ft on deep end - 19000 gal. 18" Hayward S-240 sand filter. 250K BTU Pentair MasterTemp heater. Hayward 3/4 HP Super Pump.

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    Butterfly's Avatar
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    Re: CYA dropped, WHAT?

    Have you been backwashing lots or replacing water?

    When you did the CYA test before, are you doing it now under the same lighting (time of day, etc) as before?

    I suggest you test again this weekend and if you still get 30, that's what I'd go with.

    There are so many variables with CYA testing (temp of water, time of day w/lighting, etc) not to mention starting with a +/-10 ppm. So, consistency in how and where and when we test is important.

    Your numbers look fine. You'll repost after the overnight FC loss test?
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

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  4. Back To Top    #4
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    I have not backwashed, have not changed the water, and do not have an autofill system. I'm thinking it has to be my error somehow. New contacts maybe... If I remember correctly I tested it around the same time of day on Monday. I usually do it within an hour of getting home. I'll retest it again this weekend.

    I tested FC again around 8ish, it dropped to 5. I've added 9 cups of 6% to reach high end of target and now I'm at 8.5. I'll recheck in the weee hours of the morning and post results.
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    frustratedpoolmom's Avatar
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    Re: CYA dropped, WHAT?

    Same lighting? Indoors/outdoors with your back to the sun?
    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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    esim13's Avatar
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    Re: CYA dropped, WHAT?

    yep, outdoors, back to the sun. Last weekend it was cloudy, drizzling rain and just nasty. The pool was filled almost to the top of the skimmer with rainwater. Yesterday, I barely backwashed, just for a second to get a few bubbles out of the pump basket. I don't think it could have dropped the water by much nor the CYA. It was just a quick on off. At any rate, I'll do the overnight FC and I'll retest CYA tomorrow or Sunday.
    Thanks everyone!!
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    Butterfly's Avatar
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    Re: CYA dropped, WHAT?

    Quote Originally Posted by esim13
    New contacts maybe...
    Now we understand!
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  8. Back To Top    #8
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    FC held overnight 8.5 when I went to bed, 8.5 in the wee hours of the morn!
    I retested CYA just out of curiosity and it is still roughly 30-35. It's cloudy today, a bit overcast but still bright out. I was thinking of backwashing this morning, pressure's up a bit and I didn't backwash after I shocked earlier in the week. How much will this affect my CYA level, ya think? I don't have any stabilizer but I do have some leftover pucks from last year. What do y'all think - should I add some to help raise CYA a bit?
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    JasonLion's Avatar
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    Re: CYA dropped, WHAT?

    Backwashing once shouldn't have much effect on the CYA level. Backwashing over and over through a whole season has a noticeable effect on the CYA level.

    Since it is early in the season, you will want to raise your CYA level to around 50. Otherwise it will fall below 30 (get too low) at some point during the season. Using some leftover pucks is one way to do that, though it will only raise CYA very slowly, and you need to watch to make sure that it doesn't reduce the PH too much.
    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

  10. Back To Top    #10
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    I have a chlorine floater how many pucks should I put in it?
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    Tim23's Avatar
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    Re: CYA dropped, WHAT?

    esim13,

    Hello, I saw that we are neighbors so I wanted to say hi! We have enjoyed TFP so much. They have helped us, get and keep a clear, "Trouble Free Pool". Because we live in the same area we most likely experience some of the same conditions with our water. Anyway, sorry to jump in on your post here. Oh and BTW our CYA stays around 40.

    Tim
    Delair 27', 52" round AGP. 19,300gal
    Waterway 22"/1.5hp pump, 2 speed/sand filter, BBB
    My BBB motto.."LESS IS MORE WITHOUT ALL THE CHORES, SO FOLLOW TFP AND IN THE END, THE POOL OWNER SCORES"!

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    Re: CYA dropped, WHAT?

    Quote Originally Posted by esim13
    I have a chlorine floater how many pucks should I put in it?
    I'd guess two at a time; I've been using 4 and my pool is not quite twice the size of yours. Anyway, start there and see how it goes.
    --paulr
    BBB "Intermediate Swimmer"
    IG plaster pool 18.5K gal, Hayward Pro-Grid DE filter, 3/4 HP Hydramax II; Polaris 380, 3/4 HP booster
    AG spa 325 gal, probably Sundance of some kind
    Water testing instructions on one page

  13. Back To Top    #13
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    Hi Tim We're actually closer - I'm in Denham. I absolutely LOVE TFP. I've been telling everyone about it. Everyone.. I see pools from the road while I'm driving and wish I could stick something in their mailbox .. Anywho - Thanks for the hello!
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    Tim23's Avatar
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    Re: CYA dropped, WHAT?

    esim13,

    I do service work and I see a lot of pools. I also tell people/customers about TFP and the BBB method. Can't beat a good thing. Have a good day.

    Tim
    Delair 27', 52" round AGP. 19,300gal
    Waterway 22"/1.5hp pump, 2 speed/sand filter, BBB
    My BBB motto.."LESS IS MORE WITHOUT ALL THE CHORES, SO FOLLOW TFP AND IN THE END, THE POOL OWNER SCORES"!

  15. Back To Top    #15
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    fyi, my tablets/pucks are trichlor. ph was 7.6 yesterday. I've added two pucks to floater and will keep an eye on ph. Should I worry about TA too?
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

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    JasonLion's Avatar
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    Re: CYA dropped, WHAT?

    If your PH is constantly going up, you might want to lower the TA, but otherwise I would leave it alone.
    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

  17. Back To Top    #17
    frustratedpoolmom's Avatar
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    Re: CYA dropped, WHAT?

    If you mean because the trichlor lowers PH and TA, yes, just monitor them both and keep the TA above 100 with baking soda.
    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

  18. Back To Top    #18

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    Re: CYA dropped, WHAT?

    Just a quick hello from down the river a bit. My AG pool will be finished tomorrow (I hope), but it's my second one so I'm not really a newbie. 3-inch tabs in a floater will raise CYA and FC, but your FC is high enough already at 8.5 so definitely no more bleach while the floater is working. I'd go with one tab until the FC dropped to around 5 or so, then add the second. Or you could just get some CYA and do the sock in front of the return jet thing.
    15'x30'x54" oval AG; 12,500 gallons; Aquatrol SWG; Cartridge filter; 2-speed, 2-HP pump; 2 return jets

  19. Back To Top    #19
    esim13's Avatar
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    Re: CYA dropped, WHAT?

    I put 2 pucks in Saturday then another one in on Sunday. I tested today and here's what I got:
    FC 5.5
    pH 7.6
    TA 100
    CYA 50
    Could the CYA have risen in that short period of time? Should I take the 3 pucks out? (one is almost dissolved, there others are just a little smaller) I haven't added any bleach or pucks since Sunday. thanks!
    10,408 gallon, 21' round, 52 in' deep AG, half in ground
    Artesian Clear Master Plus Sand Filter, Artesian Turbo King 2 hp pump, installed June 08
    Denham Springs, Louisiana
    GEAUX TIGERS!
    Pics taken 2012
    http://i941.photobucket.com/albums/ad25 ... CN0606.jpg
    http://i941.photobucket.com/albums/ad25 ... CN0607.jpg

  20. Back To Top    #20

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    Re: CYA dropped, WHAT?

    I always add 1 tablet per 5k gallons.

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