Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: CYA Question: How Much is Too Much?

  1. Back To Top    #1
    WaterWoman's Avatar
    Join Date
    May 2008
    Location
    Sacramento, CA area
    Posts
    139

    CYA Question: How Much is Too Much?

    Hi guys!

    I have a question about CYA...

    My original thread about the pool is here: my-giant-pond-is-almost-a-real-pool-and-some-questions-t15311.html

    Initially (about a month ago), I added about 64 oz. of CYA (it's what I had on hand at the time). I put it in an old nylon and then put that inside a tube sock, and hung that in front of a return. It took more than a week for it to dissolve that way, about 10 days altogether. After doing that, and waiting a week to test the levels, my CYA tested at around 20 ppm. Last night, I finally added the rest of what was needed according to the pool calculator to get it up to around 40 ppm. However, I decided to skip the nylon stocking inside the tube sock, since most people said they just put it in a tube sock. Maybe I should've left the nylon stocking in there, too, because when I got up his morning, the tube sock was EMPTY. (I also think I may have inadvertently added a few ounces too much?) I really don't know what could have happened for it to have dissolved that quickly this time! I'm not seeing any undissolved substance in the pool, no clouds of anything anywhere. I turned the pump on high and put the vacuum in just in case, though, and have been running the vacuum for a couple of hours so far this afternoon. Everything seems to be working OK -- pump, skimmer, filter, etc.

    I decided to test the CYA just because... I know I'm supposed to wait a week, but this is unusual, and I'm concerned. I tested the pH and FC, too.

    FC: 5 (have been targeting for 5-6 range)
    pH: 7.2 (was 7.5 prior to this)
    CYA: 60

    OK, so that seems high on the CYA, above the target level which was 40-50. This IS a sunbelt region, and the pool gets a lot of sun every day, but is this going to be too much? I'm a little freaked out about this. Is this going to cause problems? What should I do???

    Thanks!
    20,000 gallon in-ground gunite ~ sand filter (62 gpm) w/Vari-Flo valve (75 gpm) ~ 1.0 HP dual-speed pump

  2. Back To Top    #2
    reebok's Avatar
    Join Date
    Apr 2009
    Location
    Lakeland, FL
    Posts
    1,268

    Re: CYA Question: How Much is Too Much?

    can you confirm how you tested the cya?
    what you do is follow the chart. mine is at 70.
    pool-school/chlorine_cya_chart_shock
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

  3. Back To Top    #3
    WaterWoman's Avatar
    Join Date
    May 2008
    Location
    Sacramento, CA area
    Posts
    139

    Re: CYA Question: How Much is Too Much?

    Quote Originally Posted by reebok
    can you confirm how you tested the cya?
    what you do is follow the chart. mine is at 70.
    pool-school/chlorine_cya_chart_shock
    I used the CYA testing procedure in the Taylor test kit. Filled the little vial to 7 mL, added the CYA reagent to 14 mL, capped and mixed for 30 seconds, then slowly poured it into the CYA test tube until the black dot completely disappeared when held at waist level. That is the correct procedure, right? I got around 60 ppm when the dot disappeared. So, if it's at 60, I'm probably OK? Is there a chance it will go higher? I'm concerned that it all dissipated into the water so quickly.
    20,000 gallon in-ground gunite ~ sand filter (62 gpm) w/Vari-Flo valve (75 gpm) ~ 1.0 HP dual-speed pump

  4. Back To Top    #4
    reebok's Avatar
    Join Date
    Apr 2009
    Location
    Lakeland, FL
    Posts
    1,268

    Re: CYA Question: How Much is Too Much?

    it shouldn't matter. it sounds like you did fine, just overshot somehow. of course there is a +/- 10ppm error in the cya test.
    I suppose it could go up higher, you can test again in a week and see. in the mean time I would follow the 60ppm level on the chart at minimum.
    16x32 21,000 gallon in-ground exposed aggregate, 1.5hp pump, 120 sqft catridge filter, birdcage, solar panels, aquavac tigershark qc robot.

  5. Back To Top    #5
    WaterWoman's Avatar
    Join Date
    May 2008
    Location
    Sacramento, CA area
    Posts
    139

    Re: CYA Question: How Much is Too Much?

    OK, thanks. So, I can stop panicking now?

    (I just can't figure out why it dissolved overnight like that. I was shocked!)
    20,000 gallon in-ground gunite ~ sand filter (62 gpm) w/Vari-Flo valve (75 gpm) ~ 1.0 HP dual-speed pump

  6. Back To Top    #6
    TizMe's Avatar
    Join Date
    Aug 2007
    Location
    Covington, Georgia
    Posts
    920

    Re: CYA Question: How Much is Too Much?

    Perhaps without the nylon stocking it allowed the water to pass more quickly through the more porous sock so it dissolved faster. I throw in mine the skimmer basket and it dissolves overnight as well .......
    Les
    Don't have a pool right now. Just sharing what I have learned over the years!
    Helpful Links:
    Pool School,Pool Calculator,Cl/CYA Shock Chart,TF Test Kit
    Doing BBB and loving it!

  7. Back To Top    #7
    WaterWoman's Avatar
    Join Date
    May 2008
    Location
    Sacramento, CA area
    Posts
    139

    Re: CYA Question: How Much is Too Much?

    Quote Originally Posted by TizMe
    Perhaps without the nylon stocking it allowed the water to pass more quickly through the more porous sock so it dissolved faster. I throw in mine the skimmer basket and it dissolves overnight as well .......
    That's probably it. I just wasn't expecting that, being a newbie and all! Thanks.
    20,000 gallon in-ground gunite ~ sand filter (62 gpm) w/Vari-Flo valve (75 gpm) ~ 1.0 HP dual-speed pump

Posting Permissions

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