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

Thread: Sudden loss of CYA

  1. Back To Top    #1

    Sudden loss of CYA

    Hey everyone! I have been following the instructions in the article about turning my green swamp into a sparkling oasis and I have ran into a possibly weird predicament....Once I brought the pool up to shock level I was testing the water ALOT and I always maintained a 40 ppm CYA level and followed all of the guidelines for chlorine levels, etc... The water is now crystal clear (FINALLY) but my last test results showed 0 TC, 0 FC, 7.6 pH, 120 TA, 425 CH, 5 CYA, and 4600 TDS... I know the CH and TDS are high but my question is this...
    What happened to my CYA??? I thought that it only went away due to dilution? I was so concerned that I went to the local store and they tested it 4 times and got the same results...Can anyone explain what might be happening?

    BTW...No noticeable splash out and definitely no refill/rain...we did swim for the first time this year between tests if that matters...

    Thanks for any help!!!
    18000 Gallon, IG, Gunite, Hayward C1200 Star Clear Plus Cartridge Filter, 120 GPM flow rate, 1 hp pump

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: Sudden loss of CYA

    Welcome to TFP!!!

    I am a little confused, you said you are following the Swamp article and presumably the shock process as described in Pool School. Yet, the test kits we recommend do not report TDS and the minimum on the CYA test is 20ppm. So what kit are you using exactly to get your test results?

    Have you seen any higher levels of CC?
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  3. Back To Top    #3

    Re: Sudden loss of CYA

    As a home renter, I admittedly have not purchased a recommended test kit, but instead I was using the test strips left by the owner to make sure I was above shock level for FC and I was at the pool store each day during the shock to get more accurate readings (TC, FC, CC, pH, TA, CH, CYA, TDS). once I was sure achieved total algae death I started to allow the FC levels to drop and went 3 days without a pool store test, again using the test strips to watch general FC levels...The strips give ranges but appeared reasonably accurate when cross checked against the pool store test, leading me to believe that the results were reliable...When I saw that my CYA went below it's previously maintained level I went to the pool store and it was confirmed there...
    18000 Gallon, IG, Gunite, Hayward C1200 Star Clear Plus Cartridge Filter, 120 GPM flow rate, 1 hp pump

  4. Back To Top    #4
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: Sudden loss of CYA

    I am not sure which is worse, test strips or pool store testing. I would certainly not trust the CYA level from either source.

    You can get the CYA test in the cheaper HTH test kit from Walmart, but you will still be lacking the FAS-DPD chlorine test (which is required for the shock process, so not sure how well you managed that ... might have saved the cost of the test kit in reduced chemicals if done properly).
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  5. Back To Top    #5

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

    Re: Sudden loss of CYA

    You need a good test kit. Either a TF-100 or a Taylor K-2006. www.tftestkits.net

  6. Back To Top    #6

    Re: Sudden loss of CYA

    Fair points and I will most definitely invest in a good kit the second I close on my new house...but, why after so many consistent results from both tests...might it suddenly fall?

    Or are you guys just politely saying that it cant fall like that without dilution and that I am using bad tests...?haha
    18000 Gallon, IG, Gunite, Hayward C1200 Star Clear Plus Cartridge Filter, 120 GPM flow rate, 1 hp pump

  7. Back To Top    #7

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

    Re: Sudden loss of CYA

    #1 is inferior quality testing
    #2 is CYA loss over winter from biologic activity in the water
    #3 is a leak

  8. Back To Top    #8
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: Sudden loss of CYA

    CYA does not go anywhere unless you replace water. Or ... you get the magic bacteria that convert it into ammonia ... but that is something that happens over the winter sometimes and not in the middle of clearing out the pool.

    So, we have no way of explaining your observations besides relying on past experience which says test strips are bad.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  9. Back To Top    #9

    Re: Sudden loss of CYA

    Muchos Gracias! And I really appreciate everyone taking a second to look! I figured I wasn't going to be the one who defied the laws of Chemistry but I was hoping...
    18000 Gallon, IG, Gunite, Hayward C1200 Star Clear Plus Cartridge Filter, 120 GPM flow rate, 1 hp pump

  10. Back To Top    #10
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,965

    Re: Sudden loss of CYA

    Quote Originally Posted by jblizzle
    I am not sure which is worse, test strips or pool store testing. I would certainly not trust the CYA level from either source.
    Ditto!
    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
  •