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

Thread: Shocking details

  1. Back To Top    #1

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Shocking details

    I am in the midst of shocking the pool. The CC has been 1 and the FC has been difficult to keep up using the TriChlor pucks. I am in the midst of changing to BBB.

    I can give numbers later if they don't make sense.

    When does one check the FC after the addition? minutes? hours?
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  2. Back To Top    #2

    Join Date
    Jan 2009
    Location
    Cupertino, CA
    Posts
    1,966

    Re: Shocking details

    Figure on checking 30-60 minutes after adding; pump on the whole time of course.

    Trichlor is no good for shocking because it adds chlorine relatively slowly. Are you in the "use 'em up 'cause I already have 'em" mode? Stop using the pucks now and save them for when you go on vacation. What's your CYA level? (morbid curiosity)
    --paulr
    BBB "Intermediate Swimmer"
    IG plaster pool 18.5K gal, Hayward Pro-Grid DE filter, 3/4 HP Hydramax II; Polaris 380, 3/4 HP booster
    AG spa 325 gal, probably Sundance of some kind
    Water testing instructions on one page

  3. Back To Top    #3

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    Sorry, I was tired and it was late.

    I have stopped the trichlor after 3 summers of essentially no problems and started yesterday using bleach for FC and shocking due to the CYA issues. Pool is clear as a bell. No smell. Looks perfect. Yesterday morning, my numbers using FAS-DPD (Taylor) were:

    temp 78
    pH 7.0
    TA 130
    CYA 60-70
    CH 350
    FC .5
    CC 1

    I added some borax to try to get pH ~ 7.3 or so. I added some bleach to get me up to 5 ppm. Remeasured later in the day and it was 1. Added more bleach to get me to 6 and got up to 3.5. pH was ~ 7.3. I decided to shock.

    Added enough bleach for a goal of 18, 2 hours later FC=9 and CC=1. Added bleach to get me to 20 ppm. Half hour later (when I posted) the FC was 11. When to bed frustrated.

    Today, ~ 14 hours after last shock addition. Pool still crystal clear.

    TA = 140
    FC=1
    CC=.5
    pH= 7.0



    I'm about to go to pool store to see if they confirm my most recent numbers.

    Is my CYA too high or is there some organic withcraft going on?

    I'm about to pick up a S_ _ tload more bleach. And back to my day job.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

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

    Re: Shocking details

    sounds like organics. you can try an overnight fc loss test, but you're losing a ton, plus with a cc of 1 you need to shock anyway and that also indicates organics.. you're definitely adding the correct amount, right?
    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

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    I'm using the amount recommended by the pool calculator.

    I also had Leslie's check the numbers and they were pretty close to mine. Nothing glaringly different except they thought the TA was 90. It hasn't been that low since I bought the house 4 years ago. I had them test CYA and ammonia also - CYA 60, +3 ammonia.

    I agree that it is likely the "organics". Shocking again soon.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: Shocking details

    An ammonia level of 3 is rather high. You never want ammonia to be above zero. If correct, that will require a significant amount of chlorine to clear out.
    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

  7. Back To Top    #7

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    Thanks. I am starting to realize that. I'm not sure of the units - it was just a dipstick - eyeball kinda thing.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  8. Back To Top    #8

    Re: Shocking details

    Shocking is not a one-time addition of chlorine, nor is it necessarily a 2 or 3 day process. You need to keep your pool at shock level until 1) you can hold FC overnight (1pm loss is generally considered acceptible) and 2) you have <0.5ppm CC's.

    By looking at your numbers, you never finished shocking; you got frustrated and quit, which I totally understand!!
    Try again, and don't give up until your water meets the above two criteria!

    8000 gallon 20' x 48" round vinyl frame pool, 12" sand filter (don't have the specs on the pump), TF100 test kit
    Handy Links: PoolMath, TF-100 Test Kit, Pool School, CYA-Chlorine Chart
    "Shock" is a process, not a product!

  9. Back To Top    #9

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    Thanks for your input. I was tired last night more than I was frustrated though.

    I am a bit frustrated because I have never really had to shock my pool like this over the past 3 seasons. I did the non-chlorine shock (toss in and forget) maybe 3 to 4 times during the season (excluding opening and closing) and used the trichlor pucks and occasionally had to add base to raise the pH. I usually would need a baskwash 1-2 times per season. The pool was always in good shape and I would add pucks and test ~ 1 weekly. Ran a Ray-Vac most of the time when I wasn't swimming. Obviously, this is a different problem than I have experienced. I could not keep the FC up.

    I just had an espresso and am about to start at it again. Thanks for the encouragement.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  10. Back To Top    #10
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,963

    Re: Shocking details

    Sorry to hear of your troubles. If you can get the 10-12.5% strength it will mean a lot less jugs to deal with....
    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

  11. Back To Top    #11

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    I got the 12% to start with, but then found I can get it for ~ 75% of the cost in the more dilute solution from a different store. I went for the cheaper - a side benefit is the increased exercise carrying it .

    For those interested - I did get it up to shock levels ( >18) using the calculated amount this time. It started at 22.5 and drifted down to 18.5 after several hours. My aerator was on full steam at that point. I turned it off in case that increases FC losses. CC =.5 . I didn't bump it up and will retest in AM to see if it passes.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  12. Back To Top    #12

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    Fast forward 48 hours. Well, the overnight test wasn't even close. Since then I have been maintaining FC between 18-30, typically losing ~ 1 ppm every 1 hour. That is a WHOLE LOT a bleach. Still CC < or = .5. Water and pool has never looked better. SO, despite my filter pressure being ~2-3 above baseline, I backwashed. It was pretty brown yucky looking stuff. Like the Schuylkyll River after a huge rainstorm. Hopefully, that was the culprit. Bumped the FC back up to 22 ppm. I'll let you know.

    Edit: Oh, BTW, the testing chemicals go quickly unless the sample is diluted.
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  13. Back To Top    #13

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    The backwashing helped, but did not cure the problem. I lost only 3 ppm FC overnight, from 11 to 8. That's the best I've done by far. The CC is still essentially 0. The water is still crystal. The DE filter was disassembled and cleaned. There was still some old stuff caked in there. I now remember that I did not disassemble last fall when closing, like I had the prior 2 seasons. I just backwashed. Maybe that's the problem. I also read here that backwashing includes the "rinse" cycle. There is no mention of that in the instructions with the filter. Also. I measured my DE cup with an accurate scale. .75 lbs per cup instead of my instructed .5 lbs. I may have been overdosing the DE. So anyway...

    I'll try another overnight test tonight and get ready for some more shocking if it doesn't pass.

    Oh, does anyone get itchy hands after handling the DE?
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

  14. Back To Top    #14
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: Shocking details

    Keep shocking, you are making progress. The ammonia most likely came from CYA that had been broken down by bacteria over the winter.

    DE is a skin irritant, you should wear gloves when handling it.
    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

  15. Back To Top    #15

    Join Date
    Jun 2009
    Location
    Northern Philly Burbs
    Posts
    60

    Re: Shocking details

    I think that the CC held overnight at 20 ppm. Essentially no CC. Water clear. Getting TA down with acid addition and aeration over the past 24 hours. ( 150 to 110 now).

    The troops are on the way. ~ 10 people or so. Ribs are cooking. Homemade wine, beer and sparking cider at the ready. They won't mind the high FC.

    In the end, I am fairly certain that the "unclean" filter was the root of my evil. I will always do a full cleaning at fall closing ( or pool opening) and appropriately dose the DE, now that I have measured my DE "scoop" accurately.

    In the future, it may be worthwhile recommending that posters consider a filter backwash or cleaning in a clear pool with a high chlorine demand.

    Thanks again for the help everyone. Happy 4th for those who celebrate it!
    25000 gal inground freeform plaster pool with spillover hot tub. 1.5 hp PacFab Challenger pump, Hayward DE filter, Natural Gas heater, BBB convert 2009, Aquasol solar panels on ground rack 2010, PS-4 controller 2010, Rocky roller, SWG 2011.

Posting Permissions

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