Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: CYA too HIGH?

  1. Back To Top    #1

    CYA too HIGH?

    Ok so I think I have my CYA to high, I hadn't checked since I topped it up when I opened the pool 1 month ago and today I got a reading of 70, my goal was 40? oops! I am afraid I have goofed up. Pool looks great haven't had any problems so far and we have swam several times. It has been rather rainey so we have been draining alot. Should I just adjust my Chlorine levels based on your CYA chart under pools school?
    21 ft Round Dough Boy
    3/4 horsepower Dough Boy PowerPak II pump
    Vinyl Liner
    baqua goo convert

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: CYA too HIGH?

    Yes, raise the FC target to between 5 and 10 for now. Over a lot of time the CYA level will go down on it's own.
    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

  3. Back To Top    #3

    Re: CYA too HIGH?

    so should I shoot for say a medium number of 7? or shoot for 10?
    21 ft Round Dough Boy
    3/4 horsepower Dough Boy PowerPak II pump
    Vinyl Liner
    baqua goo convert

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: CYA too HIGH?

    The idea is to make sure FC never goes below 5. FC will be lowest right before you add chlorine. Just at first I would start at the high end of the range. Then if the FC level the next day is too high, try a somewhat lower starting level. If the FC level the next day is too low, try a somewhat higher starting level. Look for something that gives you a little extra margin, in case there is a day that uses up a little more chlorine than you expect it to.
    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

  5. Back To Top    #5
    Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,045

    Re: CYA too HIGH?

    Quote Originally Posted by bearclaw20
    so should I shoot for say a medium number of 7? or shoot for 10?
    5 is your minimum and 10 is your target I suggest you use 10 as your target for your evening dose of chlorine.
    Don't allow your FC to go below the minimum for your CYA.

    ETA: Jason types really fast
    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!

  6. Back To Top    #6

    Re: CYA too HIGH?

    Quote Originally Posted by JasonLion
    Over a lot of time the CYA level will go down on it's own.
    What is considered a lot of time? Is there a calculation like x points over 1 year? Here in my area of Florida it is not uncommon for 1 - 3 inches of rain during the week. At this point draining our pool 1/2 is not in the budget (water bill wise). With new rainfall this should increase the rate of that the CYA goes down? Am I correct in this thinking?
    10k gal, marcite, 1 HP pump, Filter: Cartridge 75 GPM, Pentair Cl Feeder 320, Hayward Navigator cleaner, TF Test Kit's TF100

  7. Back To Top    #7
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: CYA too HIGH?

    CYA goes down for a number of different reasons, each of which acts somewhat differently on different pools, so there is no way to give an exact number.

    When water is splashed out, it takes CYA along with it. Likewise, if the pool overflows and water is lost, or if you have an automatic overflow drain, CYA will be lost. CYA is also lost if you backwash your filter (if you have a filter that needs backwashing). Also, CYA breaks down very slowly over time.

    In a typical pool this means that CYA can fall from 50 to about 30 over the course of an entire swimming season. However, if you backwash very frequently, or have lots of kids splashing all the time, or huge amounts of rain causing water to overflow, CYA can go down much more quickly. Likewise, if your pool loses very little water for reasons other than evaporation, your CYA level might go down only a tiny amount.
    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

  8. Back To Top    #8
    dmanb2b's Avatar
    Join Date
    Apr 2009
    Location
    NY
    Posts
    3,728

    Re: CYA too HIGH?

    your correct...if you CYA is currently 70 and over time 1/2 your pool water is replaced by rain, it would come down to around 30-40ppm...for now, just keep the FC levels up.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

    Pool School, TFTestKits, Pool Calculator

  9. Back To Top    #9
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    15,422

    Re: CYA too HIGH?

    70 is quite usable. If you get a lot of direct sun, it's probably good.

    Initially you'll need more bleach to get the FC up to the higher level, but daily consumption won't really be any different than if you had 40 ppm. My pool is doing fine despite being stuck with 140 ppm CYA.

    You'll have to use the powder and drops to test instead of the color matching, that's all.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  10. Back To Top    #10

    Re: CYA too HIGH?

    Quote Originally Posted by Richard320
    You'll have to use the powder and drops to test instead of the color matching, that's all.
    I actually like that method better as I have a bear of a time reading the differences between the yellow and reds of the basic test. The chlorine is not that bad, but I need to have my wife look at the pH results. I am not color blind, but it making me wonder.
    10k gal, marcite, 1 HP pump, Filter: Cartridge 75 GPM, Pentair Cl Feeder 320, Hayward Navigator cleaner, TF Test Kit's TF100

Posting Permissions

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