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Thread: CYA Help

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    CYA Help

    Hello! I am new here and really appreciate the wealth of knowledge on these forums and web pages.

    Some information about my setup.

    Inground pool, 24000 gallons.

    Solar cover on whenever the pool is not in use, sometimes i leave it off during hot days.

    Pool is heated, stays around 86 degrees.

    I use a New Water cycler pack system as well as algecide cartridges.

    Water is crystal clear and all my levels seem good except my CYA.

    To test my pool I use 2 methods
    1. Amazon.com : AquaChek 551236 7-Way 100 Count Pool Water Test Strips : Swimming Pool Liquid Test Kits : Patio, Lawn Garden
    I found these strips are extremely accurate when I test against my secondary method.

    2. Amazon.com : TAYLOR TECHNOLOGIES INC K-2006 TEST KIT COMP CHLORINE FAS-DPD : Swimming Pool Liquid Test Kits : Patio, Lawn Garden
    Taylor K-2006


    My readings as of today are

    Temp: 86 deg.
    FC: 4.5
    PH: 7.4
    TA: 100
    CH: 240
    CYA: ~130 (verified with both strips and Taylor)

    So everything I've read states my CYA is too high and other than some bacteria option to lower it, that didn't seem to get good reviews. My only option is removing and replacing water.

    My questions are the following

    1. Do I need to lower my CYA w/ my other readings?
    2. Are my other readings while in the proper range, valid if my CYA is too high?
    3. Do I need to anything at all considering the pool clarity?
    4. Can people swim in the pool at my current levels safely?

    I'm still learning as I go here so any advice would be appreciated here.

    I am also interested in hearing opinions about replacing my cycler packs with liquid bleach or some alternative to avoid CYA issues. But i'll do another post for that.

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    jeffchap's Avatar
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    Re: CYA Help

    The minimum FC to insure your pool is sanitary is 9 ppm,and your target level should be 14. So you need to bring your FC level up with something that will not raise your CYA any higher. Bleach is what you need to do this. You can use the PoolMath link at the top of the page to calculate how much bleach to add.





    Your other levels are all fine, and once you get your FC above 9, your pool will be safe to swim in. You can also discontinue the use of algaecides at that point, as chlorine alone will prevent algae growth and most algaecides add metals to your water, which can cause staining, green hair, etc. They are unnecessary with sufficient chlorine present.





    The problem with CYA as high as yours is that should you experience an algae outbreak, you're going to need to bring your FC to 52 ppm in order to clear it up. That will require a lot of bleach, ie. $$$.





    But as long as you are diligent to maintain no less than 9 ppm, and personally I'd stay above 12 at all times, you should be fine for the rest of the year.





    As you know, draining and refilling is the only proven way to lower your CYA. You can do this gradually by backflushing and vacuuming to waste and refilling. But you must discontinue using any chlorine source that adds CYA immediately.
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    Re: CYA Help

    Would you recommend long-term I discontinue the use of the chlorinator cartridges and stick with straight liquid bleach? Can you tell me the pros and cons of that?


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    Re: CYA Help

    Quote Originally Posted by srberube View Post
    Would you recommend long-term I discontinue the use of the chlorinator cartridges and stick with straight liquid bleach? Can you tell me the pros and cons of that?

    Sent from my SM-G935V using Tapatalk
    you probably already found the main problem with that- they're constantly raising your CYA level which in turn will require increased FC level to keep your pool sanitary. Liquid chlorine increases only FC.

    BTW Taylor test kit has upper range for CYA of 100- how did you get 130?
    44k plaster pool, Pentair 011018 pump, DE6020 filter, LED lights, K2006 test kit

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    Re: CYA Help

    The test strips had a higher range, I'll be bringing a sample to my local pool supply center tomorrow for a more accurate reading.


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    Re: CYA Help

    I wouldn't put pool store testing much above guess strips. They're both terrible. If you have a Taylor 2006 that is better than either.

    The pros of liquid chlorine is that you only add chlorine, not other "stuff". The cons are you have to haul bleach. If that is too much effort there is always SWG.

    If your CYA is 130 you need to replace at LEAST 50% of your water.
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    Re: CYA Help

    Yes I have a Taylor 2006 kit, but as another user stated I can only test up to 100. The test strips seem pretty accurate. I use the Taylor as a baseline to judge their accuracy. But in this case the test strips appear to have a higher test range for CYA.

    I don't mind hauling bleach so I may really look into that. Tomorrow I'll have the pool center give me a cya reading if they can. If I need to replace half the water so be it


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    Re: CYA Help

    Quote Originally Posted by srberube View Post
    The test strips had a higher range, I'll be bringing a sample to my local pool supply center tomorrow for a more accurate reading.

    Sent from my SM-G935V using Tapatalk
    you're funny: having K2006 you're going to pool center to do the test? Why not dilute pool water sample 1:1 with distilled water or tap water in this case and do it yourself?
    44k plaster pool, Pentair 011018 pump, DE6020 filter, LED lights, K2006 test kit

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    Re: CYA Help

    Can you give me more information on what you mean? I'll try anything I love learning this stuff and in some areas I'm confident but not this one. The only reason I would take it to the pool places try to get a more accurate above 100 reading for cya. But it sounds like I don't have to replace 50% of the water immediately it sounds like I could do something like 10% a day over a week period of time to get an accumulated 50% replaced


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    Re: CYA Help

    Here you go, Pool School - Extended Test Kit Directions

    Trust your test results. We do.
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    Re: CYA Help

    Quote Originally Posted by pooldv View Post
    Here you go, Pool School - Extended Test Kit Directions

    Trust your test results. We do.
    Thanks! Do you have any idea if I can drain water from the shallow end while at the same time put a hose in the deep end and to kind of keep the water level the same but replace the water at the same time? I'm trying to see if there are any local services that can do it for me but I'm not having much luck I'm in New Hampshire.


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    Re: CYA Help

    Quote Originally Posted by jeffchap View Post
    The minimum FC to insure your pool is sanitary is 9 ppm,and your target level should be 14. So you need to bring your FC level up with something that will not raise your CYA any higher. Bleach is what you need to do this. You can use the PoolMath link at the top of the page to calculate how much bleach to add.





    Your other levels are all fine, and once you get your FC above 9, your pool will be safe to swim in. You can also discontinue the use of algaecides at that point, as chlorine alone will prevent algae growth and most algaecides add metals to your water, which can cause staining, green hair, etc. They are unnecessary with sufficient chlorine present.





    The problem with CYA as high as yours is that should you experience an algae outbreak, you're going to need to bring your FC to 52 ppm in order to clear it up. That will require a lot of bleach, ie. $$$.





    But as long as you are diligent to maintain no less than 9 ppm, and personally I'd stay above 12 at all times, you should be fine for the rest of the year.





    As you know, draining and refilling is the only proven way to lower your CYA. You can do this gradually by backflushing and vacuuming to waste and refilling. But you must discontinue using any chlorine source that adds CYA immediately.
    I'll turn my chlorinator cartridge up tomorrow which should raise my free chlorine. This will probably raise my cya is well I assume. I wonder if I can do a balance of liquid bleach in my chlorinator cartridges. I'll do some more research clearly thank you all for your help


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    Mod Squad pooldv's Avatar
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    Re: CYA Help

    What do you mean: do a balance of liquid bleach in my chlorinator cartridges?

    Yes, the pucks will raise your cya. More here, Pool School - How to Chlorinate Your Pool

    I have seen some people put the hose at the bottom of the deep end and drain from the opposite end at the top. With a theory that the warm, high cya water will stay toward the top. I don't know how well that works. Why not drain a couple of feet out and refill? We recommend leaving a foot of water in the shallow we'd if a vinyl pool to prevent liner shifting and shrinking.
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    Re: CYA Help

    Quote Originally Posted by srberube View Post
    I'll turn my chlorinator cartridge up tomorrow which should raise my free chlorine. This will probably raise my cya is well I assume. I wonder if I can do a balance of liquid bleach in my chlorinator cartridges. I'll do some more research clearly thank you all for your help

    Sent from my SM-G935V using Tapatalk


    If you continue to use the chlorinator cartridges, you will be fighting a losing battle. Chlorine burns off or is consumed daily, but the CYA you'll be adding will remain, driving your CYA level ever higher.



    You need to begin using bleach and only bleach to chlorinate your pool if you want to follow the TFP method. Ultimately it's your pool to do with as you please, but you won't find much help here with anything beyond strict adherence to our tried and proven methods.
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    Re: CYA Help

    Quote Originally Posted by srberube View Post

    I don't mind hauling bleach so I may really look into that. Tomorrow I'll have the pool center give me a cya reading if they can. If I need to replace half the water so be it

    Sent from my SM-G935V using Tapatalk
    Welcome to TFP!

    I think there is an Ocean State Job Lot store not far from you & the have 12.5% liquid shock(bleach) for $3 a gallon

    I agree with the other posts that your Taylor 2006 kit should be your standard for testing
    IG Tear Drop, Dark Gray Gunite , 27,000 gallons -Age 50+-years, very old Hayward Split Egg Sand Filter with side mount Multi-port- Hayward SP2600VSP Pump- Hayward chlorine feed (not used since finding TFP) - Laars 315K BTU Oil heater- LoopLoc Safety cover- AquaBot RAPIDS 4WD- TF-100 Test Kit w/ Speedstir- 390 Gal Hot Springs Spa Envoy installed May 2017

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    Re: CYA Help

    Quote Originally Posted by EVChargeGuy View Post
    Welcome to TFP!

    I think there is an Ocean State Job Lot store not far from you & the have 12.5% liquid shock(bleach) for $3 a gallon

    I agree with the other posts that your Taylor 2006 kit should be your standard for testing
    Yes there's one about 20 minutes away. I need to do more reading on what my frequency of bleach would be and how much I would use when I finally replace the chlorinator cartridge. I clearly have homework to do my goal is to just get through this season and then switch things up next since I only have a month and a half left.

    Today I'm going to swap about 20% of the water.


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    Re: CYA Help

    Start using bleach today...8.25% concentrated . Don't buy splashless or scented. My pool was once at 130 cya and I let it naturally go down with rain and backwashes.....I haven't had a problem since I switched to the TFP method 3 years ago
    Inground 13,200 gal Vinyl, Pentair 3/4 hp pump, Pentair Sand Dollar filter, Polaris 280

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    Re: CYA Help

    Do you, or anyone have the best link for me to start at to ditch the chlorinator system and go straight bleach? 24000 gallon inground pool.


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    Mod Squad pooldv's Avatar
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    Re: CYA Help

    Here are a few places to start in Pool School
    ABCs of Pool Water Chemistry
    Pool School - Getting Started
    TFPC for Beginners
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    Re: CYA Help

    Bottom line you need the CYA to be 40-50 if possible. I was in same place last year. Always fighting algae, buying algaecide, and shock when I had algae, pool perfect etc. The issue is that if you go by test strips or what's recommended as a FC level in a "balanced pool"(3-4 PPM at 20-30CYA) and your CYA is 100+(mine was 200+), there will not be enough active disinfectant with that high of a CYA(do some research on chlorine lock) If your chlorine gets over 90 then it locks the FC and you need to run really high chlorine to get the same disinfectant as running a lower CYA. I fought this for years I had no idea about high CYA and chlorine lock.

    You then get into a vicious cycle. The pucks add both FC and CYA and next thing you are over 100 CYA. But because you go by pool store numbers you keep FC at 3-4 when you really need FC 10+. Then you get algae so you go to store and they sell you super shock. Oh and shock has even more CYA in it than pucks. I actually went to pool store after reading all of this here and confronted them on high CYA and why did they tell me to run FC so low. They played dumb but bottom line they want to sell you expensive chemicals after you get algae that you don't need if you kept your FC at right level for your CYA. Dirty little secret the pool store will never tell you. I spent a lot of money there in 10+ years and all it was a high CYA.

    In my case I had to dilute my pool water 4:1 to get a reading of 50, its so inaccurate at that point who knows where I was at. But at a CYA of 200+ I needed a FC of 15-23 PPM. so no wonder why for years I fought algae issues running FC at 4. Pool store will never tell you that just here is some shock(that will raise your CYA even more) algaecides', phosphate reducers, etc.

    I decided last sept to bite the bullet after pool season to drain and refill. I drained about a 18 inches a shot(my pool builder recommended), then refilled and kept at it until I got to 40PPM of CYA. Took a lot and was expensive. Fast forward to this season, all I do is add bleach from Walmart keep my FC at 6. All my numbers are stable for almost a year, I go through 2/3 a gallon of 8.25% bleach a day that's it nothing else. I got a stenner pump last month to inject and have it dialed in, however I had a issue with the chlorine eating a fitting while on vacation and has a algae issue but in 3 days of SLAM I was good.

    Bite the bullet after the summer and drain and refill. In the meantime, dilute the pool water with distilled(1 part pool water 1 part distilled and measure CYA. Then multiply by 2) to see where you are really at. Then use the CYA-FC chart and keep they FC above the minimum. It will seem weird running your FC at 15PPM but what happens is probably 10-12 PPM is locked by the CYA so you only have 3-4 PPM that is available for disinfecting the water.

    My pool sparkles never looked so good. All I have put in pool in almost a year is bleach from wallyworld. No Algecide, phosfree ,pool perfect etc. Wish I found this 12 years ago would have saved thousands in unneeded chemicals. I haven't been to pool store in a year get everything(test kits and robot parts) from Amazon, 8.25% chlorine from Walmart for 2.99. My wife picks up like 5-6 jugs a week that's it.

    These guys are really good here worst you will see once folks covert is a extended SLAM usually because the OP doesn't keep the FC at SLAM level. Once you get CYA under control its smooth sailing.
    Location Charlotte NC. Pool is a IG vinyl liner, 18X36 lagoon approx. 20,000 gallons odd shaped pool with different depths. 2 skimmers, 3 returns. Hayward 1HP pump, Hayward cartridge filter, Hayward chlorine feeder, Laars 250,000 BTU heater. Stenner pump with #2 tube for chlorine injection. Leslie branded Taylor test kit

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