Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 15 of 15

Thread: CYA at 100, ok?

  1. Back To Top    #1

    CYA at 100, ok?

    Ok I just started reading the forum a couple days ago. Using Pucks to chlorinate my water for years. My pool always looks great as I do test every/every other day, but only test for FC / PH / TA. Had water tested yesterday at Leslies for CYA and was told its at 100, ouch.

    Here are my current #'s

    FC 4-5
    PH 7.5
    TA 100
    CYA 100

    Using the pool calculator, it says my FC should be from 8 to 13. Does this seem high? I always shoot to keep my pool at 2-3.

    I will be ordering a test kit this week so I can more accurate #'s. These are from one of the taylor test kits that gives a range based on the colors.

    I had my pool acid washed and refilled last April, so the high CYA is definitely from using the pucks im guessing?

    Thanks,
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CYA at 100, ok?

    Welcome to TFP!

    There are two issues here. The first is that pool store water testing can occasionally be way off, so it is difficult to decide how much to believe that test result. The second is that most common CYA tests read levels above 100 as 100, so if the test result is correct, your actual CYA level might be much higher than 100.

    Assuming your CYA level really is 100 or higher, you should replace water to get the CYA level down below 100. Very high CYA levels present numerous problems, such as requiring extremely high FC levels.

    The required FC levels depend on your CYA level. CYA buffers chlorine, reducing its effective strength, so you need to raise the FC level as the CYA level goes up to compensate.
    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
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,088

    Re: CYA at 100, ok?

    Welcome to TFP.

    Running with your CYA at 100 is a problem. You need to verify that you are at 100ppm and not a lot higher. There are testing issues that make the test inaccurate at high levels. You can dilute a sample with tap water 50-50 and your CYA reading will be close to half of your real reading. That will help you nail down where you are.

    The higher recommended chlorine level is fine, and you will never notice it. A fixed percentage of your chlorine will be bound with the CYA, so if the CYA gets, too high, your 2-3ppm FC may perform like 0.5ppm when it comes to sanitation. Running the higher level will not be noticeable to bathers.

    The best solution is to drain about 45% of your water and replace it, but you are not in an area where water is plentiful, so the higher FC levels may be preferable until your CYA naturally lowers due to splash out.

    Jason posted before me, but we described the situation a little differently, so I'll post mine anyway.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  4. Back To Top    #4
    Guest

    Re: CYA at 100, ok?

    Since you are in Phoenix, and R/O is available, you might call and get some info. I can give you a referral, if you wish.

    Welcome to the 'page!

  5. Back To Top    #5

    Join Date
    May 2007
    Location
    South Central NJ
    Posts
    3,192

    Re: CYA at 100, ok?

    45% at one shot, may be excessive in more than one way. High water tables and pool types have different safe low water levels for dilution to prevent pop ups and floats of the structure.

    In order for us to suggest the correct actions to take, wrt the dilution process, we need to know some addition information.

    Pool type
    Where to dump excess water
    Can you system do this?
    Drainage areas. High water tables make life a little interesting.

    Pictures help. Equipment pad, pool, path to drainage area are particularly telling. Descriptions help too.

    Scott
    Owner of - PoolGuyNJ LLC
    Expert Pool and Spa Repairs, Renovations, and Augmentation. Helping people decide what is the right gear for meeting their needs. Expectations Set, Expectations Met, No Surprises.

  6. Back To Top    #6

    Re: CYA at 100, ok?

    Thanks for the replies.

    I have ordered my kit, hopefully I get it B4 the weekend.

    Looks like I have some draining / refilling to do this weekend.

    What is R / O ? Reverse Osmosis?

    Thanks,
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

  7. Back To Top    #7

    Re: CYA at 100, ok?

    In the past I have drained water from my pool via the pressure release valve on my filter housing. I just run a hose to a cleanout in my house plumbing.

    OK?
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

  8. Back To Top    #8
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CYA at 100, ok?

    Yes, RO and R/O stand for reverse osmosis. RO is a treatment that removes nearly all of the dissolved solids from the water. It is handy any time you have extremely high CH or CYA levels and water is expensive or needs to be conserved.

    Pumping the pool water to the sewer system is allowed most places, but not everywhere. Aside from the question of local rules, it is fine.
    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

  9. Back To Top    #9
    Guest

    Re: CYA at 100, ok?

    Yes, R/O is Reverse Osmosis. It is not available in all parts of the Country (yet!), but it is available by you, and is an option.

  10. Back To Top    #10

    Re: CYA at 100, ok?

    I have an r/o system for my drinking water. I had not heard of an r/o system for pools.
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

  11. Back To Top    #11
    Guest

    Re: CYA at 100, ok?

    Same process; just on a much larger scale (and way more efficient than what is under your sink!)! The technology has been around for a very long time, but is just now being put to use by a handful of people who have seen what it can do to pool owners with high CH (among other things) and in areas with water restrictions and/or high water tables, to name a few. It is not available everywhere yet, and probably won't be needed in areas where water is plentiful and CH levels are low. In the southwest, where these conditions exist, it is starting to gain acceptance and growing.

  12. Back To Top    #12

    Re: CYA at 100, ok?

    Ok so I diluted my water 50% with tap water an had leslies test my cya again, still came back with a reading of 100 or more. I think I'm going to wait for my test kit and test it myself before I do any draining/refilling.

    Could my cya level really be that high? After diluting 50% with tap water an still getting a reading of 100+, that would put my cya at 200+, wow.
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

  13. Back To Top    #13
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: CYA at 100, ok?

    Quote Originally Posted by azdaren
    Ok so I diluted my water 50% with tap water an had leslies test my cya again, still came back with a reading of 100 or more. I think I'm going to wait for my test kit and test it myself before I do any draining/refilling.

    Could my cya level really be that high? After diluting 50% with tap water an still getting a reading of 100+, that would put my cya at 200+, wow.
    Yes, it could.

    When I first tested my pool I diluted and was still off the scale. Diluted again, got something like 220. I later found out that cool temperatures make it read low, so it was probably higher. The previous owner and his useless pool service liked pucks in a floater. The pool was supposedly replastered and filled with fresh water two years ago.
    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!

  14. Back To Top    #14

    Re: CYA at 100, ok?

    Got my test kit yesterday and did a full workup this morning. Here are the results.

    FC 6.5
    CC 0
    pH 7.4
    T/A 120
    CH 650
    CYA 160


    Not too thrilled about the thought of draining/refilling %75 of my pool. Do I really have any other options?
    12,500 Gal In Ground Plaster, Zodiac lm2-24 SWG, Cartridge Filter, Attached spa, Waterfall, Phoenix AZ

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

    Re: CYA at 100, ok?

    R/O is the only other option left. Since your CH is very high anyway, it would be worth it.
    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

Posting Permissions

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