Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 20 of 20

Thread: How much CYA?

  1. Back To Top    #1

    How much CYA?

    This weekend my 27' (17k gallon) AGP was setup as a salt system. Saturday I dumped in town water (no chlorine) 340 pounds of salt and 5 pounds of cyanuric acid (mostly dissolved in a bucket of hot water.) Right now my SWG is generating chlorine and the stats are the following from a AquaChek dip strip:

    Hardness 100
    Total Chlorine 1
    Free Chlorine .5-1
    pH 7.8
    Alkalinity 80
    Cyanuric Acid (either 0 or 30-50)

    I know the first order of business is to get a better test kit, which I ordered the Taylor 2000 test, but I am wondering why the CYA is so low. Is around 1 pound per 5k gallons the proper dose, or do I need more? It seems like the Aqua Rite manual suggests 10 pounds of CYA for a 17K gallon pool.

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  2. Back To Top    #2

    Join Date
    Feb 2008
    Location
    Denton, TX
    Posts
    5,061

    Re: How much CYA?

    Test strips are unreliable for CYA testing purposes. It would be best to run a sample to a pool store that uses the standard turbidimetric CYA test to check the level for you.

  3. Back To Top    #3

    Re: How much CYA?

    Quote Originally Posted by 257WbyMag
    Test strips are unreliable for CYA testing purposes. It would be best to run a sample to a pool store that uses the standard turbidimetric CYA test to check the level for you.

    Good to know, I will see what the Taylor test kit says that is coming in the mail tomorrow.

    Other than getting the chemical levels right, do I need to add anything else to a new pool? Does the new water need to be shocked?

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  4. Back To Top    #4
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: How much CYA?

    Chris,

    You should lower your pH to about 7.5 first.

    Please list your pool and equipment specs in your signature.
    This will be a big help for those trying to answer your questions.
    Go to User Control Panel (upper left under TFP logo, select Profile, then Edit Sig..)

    Also, please read recommended levels for SWCG here: pool-school/water_balance_saltwater_generator

    We recommend a CYA level of 70 to 80 for SWG pools.
    What level are you shooting for?....and how many pounds have you added so far?

    Use Jason's Pool Calculator (link in my sig) to help determine the correct amounts of chems to add.

    If you have problems, just post back and someone will be around to help.
    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!

  5. Back To Top    #5
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,965

    Re: How much CYA?

    I'm not happy right now, I typed a very nice post and it didn't post!
    Lets see, what did I say:

    Lower your PH down as advised by Butterfly...

    5 lbs would put your CYA level around 35. So assume that's your level and raise your FC accordingly. You should use liquid chlorine to raise it up to 3-4 and allow the SWG to keep it steady. It can take 5-7 days for CYA to fully dissolve and register on tests.

    Now, tomorrow night when you get your kit - turn off the SWG before you go to bed, and test the FC level. If the FC is holding overnight, shocking isn't necessary. If the FC doesn't hold- then you'll need to shock.

    If the FC holds, go ahead and add another 4-5 lbs of CYA to raise your level into range. If you have to shock, WAIT TO RAISE THE CYA LEVEL until you are done shocking. Use liquid chlorine to shock the pool.
    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

  6. Back To Top    #6

    Join Date
    May 2007
    Location
    Alabama
    Posts
    66

    Re: How much CYA?

    Quote Originally Posted by frustratedpoolmom

    It can take 5-7 days for CYA to fully dissolve and register on tests.
    I just wanted to emphasize the above point as I have fallen victim to my own impatience before and ended up with CYA levels over 120. Waste of money and water

    CYA definitely requires patience.
    24' Vinyl, AG, Sand Filter, 1 1/2 HP Hayward PowerFlo LX, BB&B

  7. Back To Top    #7

    Re: How much CYA?

    Signature updated.

    I have only added 5 pounds of CYA, it sounds like I should lower my PH, add 2-3 more pounds of CYA, make sure I can get the FC up to 3 and let it sit for a week or so? Why won't the SWG be able to produce the chlorine by itself?

    What does the "shock" setting do on my SWG?

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  8. Back To Top    #8

    Join Date
    Jan 2009
    Location
    Cupertino, CA
    Posts
    1,966

    Re: How much CYA?

    Quote Originally Posted by *chris*
    I have only added 5 pounds of CYA, it sounds like I should lower my PH, add 2-3 more pounds of CYA, make sure I can get the FC up to 3 and let it sit for a week or so? Why won't the SWG be able to produce the chlorine by itself?
    It can; but it's not fast. The point of the initial bleach dose is to get a reasonable FC level quickly, which the SWG can then maintain.
    --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

  9. Back To Top    #9
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: How much CYA?

    Quote Originally Posted by *chris*
    What does the "shock" setting do on my SWG?
    Typically it turns the cell to 100% for 24 hours, and then goes back to the previous setting. As PaulR said, that isn't actually very good for shocking by it's self because it produces chlorine too slowly, but it can be handy for maintaining shock level once you have gotten there manually.
    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
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,965

    Re: How much CYA?

    Quote Originally Posted by *chris*
    it sounds like I should lower my PH, add 2-3 more pounds of CYA, make sure I can get the FC up to 3 and let it sit for a week or so?
    No.... Don't add more CYA until you confirm the FC is holding, and you should not wait a week or so to do this.

    You expect your kit today, correct? Tonight, turn off the SWG, test the FC (which you have raised to 4 or so using liquid chlorine) and record the result. Tomorrow morning, test again BEFORE the sun hits the pool. If you lose more than 1ppm of FC, this means that you need to shock the pool and you should do this BEFORE you raise the CYA any higher than it is right now.

    IF THE FC HOLDS, you do not need to shock, and you can go ahead and raise the CYA with another 4 lbs. Retest the CYA in a week or so.

    Test your FC daily and make sure it is staying consistent.

    Yes, Lower the PH today as instructed.
    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

  11. Back To Top    #11

    Re: How much CYA?

    Interesting results this morning, the CYA was up and the pH is down. Also my FC was 3, so I guess the SWG has enough output to chlorinate the pool? I am running my 2 speed pump on low-speed 24 hours a day.

    I will test the water this evening and turn off the SWG and see what the results are in the morning.

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  12. Back To Top    #12

    Re: How much CYA?

    My Taylor test kit came tonight and I measured the following results:

    FC 3
    TC 5
    CC 2
    pH 7.6
    acid demand 2 drops dropped pH to 7.2
    TA 70ppm
    CH 90ppm
    CYA 40ppm

    So it looks like I need to increase my TA with 120oz of baking soda and 529 oz of calcium chloride to increase my CH (I think I will test this again).

    I am glad to see that the CYA measurement more or less agrees with the 5 pounds of CYA I put in the pool. It looks like 3 more pounds of CYA are required as well.

    While the pool is not sparkling clear, I can see the bottom very clearly.

    I turned off the SWG and will test everything again tomorrow morning.

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  13. Back To Top    #13
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: How much CYA?

    It looks like you are going by the default values in the Target column of the Pool Calculator. What you really want to be doing is to go by the recommended levels article at Pool School.

    There isn't any need to add CH to an above ground, vinyl liner, pool.

    Your TA is fine where it is. There isn't any need to add baking soda.

    You want to target a CYA level of 80. When it has been at least a week after you last added stabilizer and FC is holding steady, adjust the CYA level from what ever level you have at that point up to 80.
    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

  14. Back To Top    #14

    Re: How much CYA?

    Jason, I just pulled these figures from the manual of my Aqua Rite SWG. I will buy more CYA and see what my FC looks like tomorrow morning.

    Thanks!
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  15. Back To Top    #15
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,965

    Re: How much CYA?

    If your CC is 2 this means you need to shock.

    Don't raise CYA until the shock process is complete. Read How to Shock your Pool in Pool School - maintain shock level until the FC holds over night (SWG must be off) and the CC is .5 or less.
    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

  16. Back To Top    #16

    Re: How much CYA?

    I tested the pool again this morning after leaving the SWG off for 12 hours. I had to dilute the sample in half with tap water. The FC is now 4 and the CC is 0 confirmed by my wife pH is still sitting at 7.6 Besides adding more CYA, what are my next steps?

    The water is still a bit cloudy, how do I clean that up?

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  17. Back To Top    #17
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: How much CYA?

    A couple of observations. If your FC is 4 why did you have to dilute the sample? The K-2000 reads up to 5. Second, You diluted with tap water. Does it contain chlorine? Most municipal water does. And finally, You really should have ordered the K-2006 not the K-2000. That's all folks
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  18. Back To Top    #18
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: How much CYA?

    Continue to maintain the FC level between 3 and 7, and higher once you have added more CYA, and give the filter some more time to clear up the water.
    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

  19. Back To Top    #19

    Re: How much CYA?

    Quote Originally Posted by Bama Rambler
    A couple of observations. If your FC is 4 why did you have to dilute the sample? The K-2000 reads up to 5. Second, You diluted with tap water. Does it contain chlorine? Most municipal water does. And finally, You really should have ordered the K-2006 not the K-2000. That's all folks
    My tapwater does not contain chlorine. I tested both diluted and non-diluted since it seemed that I was near the top of the kit (5ppm) measurement range.

    Why should I have ordered the 2006 kit, care to elaborate?

    Jason, thanks, I will let it sit and see how it goes. Thanks for the help.

    Chris
    27' 17k gallon AGP
    Hayward 1.5hp 2 speed Powerflo pump
    Hayward Aqua Rite 25k SWG
    Hayward 24" Pro sand filter with 150 pounds zeolite

  20. Back To Top    #20
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: How much CYA?

    The K-2006 contains almost all the tests we recommend here.

    It'll test
    FC to 50ppm
    CC same
    pH
    Acid demand
    Base demand
    Total Alkalinity
    Calcium Hardness
    Cyanuric acid

    You can see a comparison of the recommended kits here.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •