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Thread: Lower CYA?

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    TexCin's Avatar
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    Lower CYA?

    I've had my IG pool for about 5 years. in 2006 I discovered the other forum and the BBB method which worked fantastic. Due to a variety of issues which included an accident which left my dad with a traumatic brain injury, commuting between Texas and Arkansas every other weekend for several months, moving my parents to Texas, yadda yadda yadda, I went back to the 3 inch puck in my automatic chlorinator due to its simplicity and my lack of time to address the pool. Now things have settled in my personal life and I am ready to get back to taking care of the pool we love and enjoy. I've kept track of chlorine only for several months and, after replacing a few of the reagents in my Taylor test kit, did a full test today. Naturally the CYA number is in outer space so before I try to fix the other problems, I am working on the CYA. According to Jason's calculator (which I love) I have to replace 60% of my water to get the CYA back within working levels. That means running 9000 gallons into my pool. I've calculated the hose is putting 4 gallons per minute in. That translates, if my math is accurate, running the hose for the next 37.5 hours. Can somebody tell me if there is any other way to lower my CYA from its current level of 100 without running that much water? Also, it seems so wasteful to dump 9000 gallons from the pool, but I have no way to store that much water other than in the pool and we've had so much rain that my yard, flower beds etc don't need the extra water. Thanks in advance for your advice and thanks to Sean for starting this forum.
    36x16 gunite, 14,500 gallons, Jandy 2.0hp VS Epump, Jandy CL460 filter, Automatic chlorinator, Jandy Legacy 400K BTU Heater, Polaris 1.5HP spa blower, 2 Colorlogic pools lights and 1 Colorlogic spa light, Polaris 3/4HP booster pump, Polaris 280 cleaner, Jandy PS4 with PDA, QuartzScapes Montego Bay plaster, OK flagstone coping, spray deck (aggregate effect) - completed 3/2011

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    TizMe's Avatar
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    Re: Lower CYA?

    Sorry to hear about your fathers injury.

    The only method I know of for reducing CYA is replacing water. You guys have had tons of rain this year and I wish we could have had some of it!
    Good Luck !
    Les
    Don't have a pool right now. Just sharing what I have learned over the years!
    Helpful Links:
    Pool School,Pool Calculator,Cl/CYA Shock Chart,TF Test Kit
    Doing BBB and loving it!

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    frustratedpoolmom's Avatar
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    Re: Lower CYA?

    You can do it more slowly, say, inches of water at a time as opposed to all at once. I did 3 seperate partial drains and refills, 2 last summer and then again at the start of this season. I brought my CYA from over 100 down to 40.

    I'm sorry for your troubles (my father is recovering from a bad stroke himself) and I know how frustrating this must be, but water replacement is really the only way. Good luck to you!
    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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    TexCin's Avatar
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    Re: Lower CYA?

    Thanks for reading and suggesting...I am going with the partial replacement over the course of 5 days...I figured out how much I had to take out today and then over the next 4 days. Hopefully I'll see levels closer to 40 when I'm done. Thanks again!
    36x16 gunite, 14,500 gallons, Jandy 2.0hp VS Epump, Jandy CL460 filter, Automatic chlorinator, Jandy Legacy 400K BTU Heater, Polaris 1.5HP spa blower, 2 Colorlogic pools lights and 1 Colorlogic spa light, Polaris 3/4HP booster pump, Polaris 280 cleaner, Jandy PS4 with PDA, QuartzScapes Montego Bay plaster, OK flagstone coping, spray deck (aggregate effect) - completed 3/2011

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    Re: Lower CYA?

    Unfortunately, partial refills/fills will cost you more water in the long run. I'd recommend if you can, do it in one shot.

    For instance, if your CYA is at 200, and your target is 50, you'd have to drain 75% of the pool.

    If you did this in three stages, where you drained 25%, you'd actually end up with the CYA as follows:

    200 * 0.75 = 150
    150 * 0.75 = 112.5
    112.5 * 0.75 = 84

    Thats pretty far off from the 50 you want, its simply a matter of dilution.

    That being said, draining 70-75% of the pool, if it is a vinyl liner, is kinda risky, especially if you have a shallow/deep end, since that will result in an empty shallow end with the liner potentially getting messed up.
    Jim

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    TexCin's Avatar
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    Re: Lower CYA?

    Wow! Thanks for the chem/math lesson...I am a dud at both. I have a gunite pool, but am still concerned about draining too much at once so I am sticking to the 5 day plan and am 1/5 of the way there! My CYA started out at 100, but until I receive my order on new (refill) reagents for my test kit, I'm unable to test again. Hopefully the reagents will arrive on the 5th day of my drain/refill schedule so I can see where I've ended up. If the formula above works, then I should be close to my goal on day 5.

    Thanks again to everyone!
    36x16 gunite, 14,500 gallons, Jandy 2.0hp VS Epump, Jandy CL460 filter, Automatic chlorinator, Jandy Legacy 400K BTU Heater, Polaris 1.5HP spa blower, 2 Colorlogic pools lights and 1 Colorlogic spa light, Polaris 3/4HP booster pump, Polaris 280 cleaner, Jandy PS4 with PDA, QuartzScapes Montego Bay plaster, OK flagstone coping, spray deck (aggregate effect) - completed 3/2011

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    revstriker's Avatar
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    Re: Lower CYA?

    Quote Originally Posted by TexCin
    Wow! Thanks for the chem/math lesson...I am a dud at both. I have a gunite pool, but am still concerned about draining too much at once so I am sticking to the 5 day plan and am 1/5 of the way there! My CYA started out at 100, but until I receive my order on new (refill) reagents for my test kit, I'm unable to test again. Hopefully the reagents will arrive on the 5th day of my drain/refill schedule so I can see where I've ended up. If the formula above works, then I should be close to my goal on day 5.

    Thanks again to everyone!
    Just doing a little math.... If you have a 15k pool and you need to replace 9k gallons, that would get your CYA from 100 to 40. If you were to split this over 5 days, you would have to replace 12,700 gallons total in order to go from 100 to 40. If you only replace 9000 gallons over 5 days, you CYA would only go down to 53.

    Anyway, good luck and I'm sure you'll get it to where you need.
    10K White Plaster Pool Built in 2007. Hayward Pump and DE Filter, Hayward Navigator, Liquidator (Removed due to issues), Solar Blanket, BBB user.

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