Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 13 of 13

Thread: Shocked and now chlorine is too high

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    Atlantic Beach, Florida
    Posts
    9

    Shocked and now chlorine is too high

    My daughter just moved into a new home with a 34,000 gallon pool here in Florida. It's marcite. The prior owner chlorinated with tablets and shocked with liquid chlorine ("when I got algae"). It looked great when we moved in, but a few days later, some algae began to appear. We tested and had some CC so we shocked (almost a week ago) with around 12 gallons of 10% chlorine. It cleared the algae and the pool looks great now. I was trying to make sure we hit "breakpoint" and I'm pretty sure we succeeded.

    Here are our current readings:

    Ph 7.4
    TA 80
    Cyan 100 (way too high for me - apparently due to prior owner's tablets)
    FC - still very high at 25 plus (can't tell for sure using my Taylor test kit even when I dilute and multiply by 5)
    Sand filter

    My question is how low does the FC have to get to be safe to swim in? Per the chart here on the website, our target FC with 100 Cyan is 12. The sun has been beating on it since Saturday and it's still very high. Not sure how long to wait - or if we should drain some to get the stabilizer down and the chlorine too.

    Thoughts?

    Thanks much.

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

    Re: Shocked and now chlorine is too high

    Welcome to TFP!!!

    First, we NEVER recommend doing what you did by adding that much chlorine at once as it can cause damage. If you have algae, we teach to use the SLAM Process. In fact, I would suggest that you should still follow this process until you pass the 3 criteria to stop.

    Second, you can not do the SLAM process without the recommended FAS-DPD chlorine test. It will read FC and CC up to 50ppm without having to try to dillute and do color matching. Get it here: FAS-DPD Chlorine Test

    Third, the first step we would suggest is replacing a LOT of water to get that CYA back down into the recommended range of 30-50ppm. See http://www.troublefreepool.com/conte...mmended-levels

    The required FC level for maintenance and SLAMing is a function of your CYA level. In reality since your CYA is so high, your FC is actually not that bad. In fact if you look at the FC/CYA Chart, if your CYA was 100ppm, your FC level should be maintained around 12ppm at all times and for SLAMing you would need to hold the FC at 39ppm. Since you CYA is higher, the FC numbers would be higher also.

    To answer you actual question, it is safe to swim up to SLAM level FC ... so if your FC is below 40ppm, you are certainly fine to swim.

    Redo the CYA test starting with 50/50 mix of pool and tap water, then add the reagent, then read the test a few times with bright indirect light and the tube at your waist. Then double the reading to get a better idea of your CYA level.
    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

    Join Date
    May 2014
    Location
    Atlantic Beach, Florida
    Posts
    9

    Re: Shocked and now chlorine is too high

    Thanks very much for the feedback. The CYA test was done at two different pool stores and one was 97 and one was 100. I definitely want to get the level down to below 50 so I guess I need to gradually start draining and refilling. I'd like to just do it and be done with it, but I don't think it's safe to take more than a foot or so of water out at a time for fear of the water table here in Florida popping it.

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

    Re: Shocked and now chlorine is too high

    OH, I thought you did this testing. If you did not, then Step 0 is to order one of the Recommended Test Kits.

    You are right that you need to be careful with draining too far.
    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
    Jan 2013
    Location
    Houston, TX
    Posts
    1,079

    Re: Shocked and now chlorine is too high

    Quote Originally Posted by bpajax View Post
    Thanks very much for the feedback. The CYA test was done at two different pool stores and one was 97 and one was 100. I definitely want to get the level down to below 50 so I guess I need to gradually start draining and refilling. I'd like to just do it and be done with it, but I don't think it's safe to take more than a foot or so of water out at a time for fear of the water table here in Florida popping it.

    Reality may be much much higher than that... definitely time for a TF-100 test kit. get a good set of numbers and we can help.

    Welcome to the forum!
    TFP Moderator Chris V. ~16K Pool & Spa, 48NSF DE, IG Plaster Circa 2000, Intermatic PE653, Challenger pump with a 2 speed B2984, 20gal stenner chlorine injection, Houston, TX
    One cannot follow Islam and Christianity at the same time, nor can one follow pool store methods and TFP at the same time.
    Pool School -- Pool Math -- TF-Test Kit

  6. Back To Top    #6
    Smykowski's Avatar
    Join Date
    Sep 2011
    Location
    Gurnee, IL (North Suburban Chi-town)
    Posts
    3,065

    Re: Shocked and now chlorine is too high

    Quote Originally Posted by karmabiker View Post
    Reality may be much much higher than that... definitely time for a TF-100 test kit.
    karma's right, which is why I want to highlight it. Most pool store cya tests (which seem to be notoriously unreliable) top out at 100. Even the good test kits that we use are only valid to 100. It is very likely that yours is way, way over 100, and there's no way to know how much. You can do a dilution with a Taylor test kit that will get you close, but I see multiple drains/refills in your future.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
    The most important article on this site - The ABCs of Pool Water Chemistry

  7. Back To Top    #7

    Join Date
    May 2014
    Location
    Atlantic Beach, Florida
    Posts
    9

    Re: Shocked and now chlorine is too high

    So I want to start draining. The more I drain at once, the less "dilution" water I will have to add to get the CYA down, but it's not safe structurally to drain out too much. Any suggestions?

  8. Back To Top    #8
    Casey's Avatar
    Join Date
    Apr 2007
    Location
    SW PA
    Posts
    10,157

    Re: Shocked and now chlorine is too high

    Drain a foot of water and refill it until you hit a reasonable CYA amount of 30-50PPM CYA. It could take several drain/refills and is much safer than just dumping the whole pool. You do NOT want it popping!
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

  9. Back To Top    #9

    Join Date
    May 2014
    Location
    Atlantic Beach, Florida
    Posts
    9

    Re: Shocked and now chlorine is too high

    Quote Originally Posted by Casey View Post
    Drain a foot of water and refill it until you hit a reasonable CYA amount of 30-50PPM CYA. It could take several drain/refills and is much safer than just dumping the whole pool. You do NOT want it popping!
    Definitely don't want it popping. Our pool popped during construction 15 years ago. The pool contractor just about died. Fortunately it was covered by his insurance. They had to totally break up the pool shell and redo the entire pool.

  10. Back To Top    #10

    Join Date
    May 2014
    Location
    Atlantic Beach, Florida
    Posts
    9

    Re: Shocked and now chlorine is too high

    I'm going to drain some of the pool to get the CYA down. Does anyone know if the CYA is more concentrated at the top or bottom of the pool? I read elsewhere that if you let the pool sit for 8 hours with no circulation, that the CYA will rise to the top. You can then remove water via a sump pump or skimmer hose from the top of the pool and get a higher concentration in your removed water - thereby requiring less water be removed overall. Thoughts?

  11. Back To Top    #11
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: Shocked and now chlorine is too high

    Not true. It is evenly distributed.
    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!

  12. Back To Top    #12
    Beens's Avatar
    Join Date
    Jul 2013
    Location
    Virginia Beach, Va
    Posts
    1,171

    Re: Shocked and now chlorine is too high

    Have you ordered a test kit yet? *don't forget* You'll need it so you can test the CYA and more accurately test your FC level so you might as well get it on it's way.
    18' x 48" (42" water depth) Intex Metal Frame 6,700 Gallons
    Hayward Power-Flo LX 1.0 HP pump
    Hayward Pro Series S166T Sand Filter
    Original Intex Floating Skimmer

  13. Back To Top    #13
    Isaac-1's Avatar
    Join Date
    May 2010
    Location
    SW Louisiana
    Posts
    6,711

    Re: Shocked and now chlorine is too high

    If your fill water is cooler than your pool water you can run a fill hose down to the deepest point of the pool while you drain from the skimmer / surface. This cooler CYA free fill water should sink and separate some from the pool water partly keeping it from high CYA water you are draining, and lower the dilution while you drain. This will not last long though, but may help a little.

    Ike
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
    ~Remember TFP counts on your donations to keep this site ad free~

Posting Permissions

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