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Thread: Do I need to SLAM? SWG issue?

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    Join Date
    May 2015

    Do I need to SLAM? SWG issue?

    It seemed my chlorine levels were drifting down quicker than expected. I did an overnight test and the FC went from 5.5 to 4, the CC is <0.5.
    My CYA is 70. Other numbers below and all look spot on.

    I've had to run my SWG at 90%, 12 hours/day and even then I am supplementing in some liquid bleach.

    I know it says to SLAM if FC drops over 1 overnight, which it did just barely... (1.5)

    Or could it just be since it's been sunny lately (my pool gets sun exposure the whole day) that I need to up the hours I am using my SWG? I just thought that 12 hours at 90% was pretty high and to still not get chlorine maintained at that level...


    FC 4 PH 7.5 CC <0.5 TA 70 CYA 70 CH 300 Salt level 3500 (Manufacturer recommends at 3000-3500)
    Inground Pool Completed April 2015
    Salt Water Generator- Nature 2 Fusion Soft
    33,500 gallons, Gunite/White Plaster
    Cartridge Filtration
    Heat Pump

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    duraleigh's Avatar
    Join Date
    Apr 2007
    Sebring, Florida

    Re: Do I need to SLAM? SWG issue?

    I just thought that 12 hours at 90% was pretty high and to still not get chlorine maintained at that level...
    Of course that depends on the capacity of your SWG. Has it's performance been degraded?, etc.

    I can say for sure that you should slam, regardless. A 1.5 ppm OCLT is excessive and needs your attention.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    needsajet's Avatar
    Join Date
    Jan 2016
    Sydney, NSW, Australia

    Re: Do I need to SLAM? SWG issue?

    The chlorine loss indicates slam, yes. Did you follow this procedure... OCLT Pool School - Perform the Overnight FC Loss Test (OCLT). It may be worthwhile doing it one more time to eliminate the possibility of testing error.

    Is the pool sparkling clear? If not what does it look like?

    Ignoring the copper and silver output for a moment, have you been able to find out the chlorine output of that unit in either pounds per day or grams per hour? There's a good possibility the SWG needs to run longer. I would turn it up to 100% in the meantime.

    Have you tested the copper level recently? If it's high, there are special procedures due to staining risk. I'm not experienced in that, but experts would need those answers either way. I'm just curious, but is it possible to turn the copper/silver apparatus off?

    Finally, I think it would be a good idea to keep your FC at or above 4 PPM as a plan develops. Use chlorinating liquid or bleach if need be, but don't take it up too fast.

    You may have already done so, but if not, search the forum for "alternative sanitizers"

    Trouble Free Pool Care (TFPC), as recommended here at TFP, does not include the use of copper and silver as sanitizers.
    12k IG salt; glass beads in plaster; K-2006C, K-1766, CCL, and Aussie 4in1 (HTH); Pentair Eco800 1.2HP VS; Zodiac SWC 1.3 lb/day (25 g/hr); 25" filter recycled glass; OKU solar panels; 1/2 HP solar pump; Rebel (Warrior) pool cleaner; FlowViz; prior pool AG 10k | Read Before Posting to get the best possible advice | ... and this helped me a lot!: TFPC for Beginners

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    mikemass's Avatar
    Join Date
    Jul 2013
    Northern Howell, NJ

    Re: Do I need to SLAM? SWG issue?

    Did you inspect your cell? Debris and/or scale on the plates can affect output performance. Most manufactures say to inspect and clean every 3 months.
    25 + year pool owner. Current pool (going on 13th year) - 38K gallon in ground Gunite/White Plaster, Spillover Spa, Hayward Cartridge Filter, Hayward 450k BTU NG Heater, Hayward Goldline Aqua Logic control with T-Cell-15 Salt Water Cell, Dolphin Explorer.

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