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Thread: Did a drain/refill, now doing a SLAM, sanity check requested

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    Bender's Avatar
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    Did a drain/refill, now doing a SLAM, sanity check requested

    I posted a while ago when I was just getting started. I just performed a drain and refill, tweaked things a bit (added acid to lower pH, added CYA to get to an appropriate level) and here's where we were after that:

    6/7 14:32 105f
    FC 2
    CC 0
    PH 7.2
    TA 130
    CH 300
    CYA 35

    I started the SLAM process with those numbers. Here's a log of what's happened since then (reading and then action taken in parens):

    6/7
    14:32 FC 2 (+2x 121oz 8.5%)
    15:41 FC 21.5
    16:25 FC 18.5 (+36oz)
    22:04 FC 20.5
    6/8
    5:05 FC 16.5 (OCLT was -4 FC)
    7:54 FC 15 (+12oz - trying to maintain 16 based on a CYA of 40)
    9:55 FC 12 (+49oz)
    12:15 FC 12.5 (+43oz)
    14:15 FC 12 (+49oz)
    16:00 FC 13 (+37oz)

    Is this how a SLAM should look? Is a lot of that loss due to the Phoenix midday sun? I was surprised to see the -4 on the OCLT due to the fact that the water is crystal clear, beautiful blue, and the CC has ranged between 0 and 1 since the refill (only got 1 once on 6/4, every other time it's been 0.5 or 0). Still seeing stuff when I sweep the bottom as I saw in my previous post (there's a picture there). I have a suction cleaner (MX8) but have not hooked up yet due to needing to SLAM after the refill.

    Tomorrow is a work day and I'm trying to figure out how to continue the SLAM process when I need to be at the office. It seems like it will be difficult to add enough before work to last until coming home at lunch, and then again to last until coming home after work. Would appreciate any comments as to whether this is the right track
    ~12k gallon in-ground, Pebble Sheen, Hayward Pro-Grid D.E. filter, Pentair WhisperFlo, Zodiac MX8, TF-100 test kit

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    Mod Squad tim5055's Avatar
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    Re: Did a drain/refill, now doing a SLAM, sanity check requested

    To my fairly newly opened eyes to TFP it looks good. The MINIMUM times you should adjust during a SLAM is twice a day and if you come home at lunch you will be well above that. The OCLT can reveal strange things as stuff can be growing in the water that you can't see

    I would think the Phoenix sun will do a number on the chlorine during the day. I'm still trying to wrap my head around your 105f temperature. My one visit to Phoenix was in late July/early August one year and i couldnt believe it. Crossing the street the asphalt felt "soft".
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Did a drain/refill, now doing a SLAM, sanity check requested

    There is no set way a SLAM should look, you are doing it right. If you are losing 4 FC overnight then something is in there. A lot of first time TFP'ers, myself included, have a very different definition of what "crystal clear" is compared to what those of us who have been using it a while call it. So there may be a haze that you aren't noticing because it has always been there. You are on the path to finding out though!

    Assuming nobody will be in the pool while you are at work you can bring it up to mustard algae level (24 in your case) in the AM and at lunch. This should keep it from dipping too low, and then back to the normal 16 in the evening and for the OCLT.
    JD - 28' Round Above Ground Pool, 17,000 Gallons. Dual speed Jacuzzi pump with cartridge filter. Dual speed 1 HP pump, Hayward S210T sand filter
    Pool School - PoolMath - HIGHLY Recommended Test Kits

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    Bender's Avatar
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    Re: Did a drain/refill, now doing a SLAM, sanity check requested

    Thanks for the sanity check, guys! I will stay the course and see what happens with the OCLT tonight. I didn't even think that swimming in it during the SLAM was an option so I'll shoot for 24 tomorrow during the day and let it settle down to 16 for overnight.
    ~12k gallon in-ground, Pebble Sheen, Hayward Pro-Grid D.E. filter, Pentair WhisperFlo, Zodiac MX8, TF-100 test kit

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    Bender's Avatar
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    Re: Did a drain/refill, now doing a SLAM, sanity check requested

    So the SLAM went wonderfully once I realized my pool was missing a skimmer/main drain diverter and the algae was illegally squatting in the drain pipe! Once I got a diverter and got the main drain working it all cleared out almost instantly. Yay! The pool looks far more clear and crisp than I've ever seen it, I think I understand what "crystal clear" really is now!

    Here are some numbers from yesterday:

    6/14 at 14:36 (air temp ~102f, water temp at 16:41 86f)
    FC 4
    CC 0
    pH 7.8
    TA 120
    CH 275
    CYA 50

    So my difficulty at the moment is in keeping the pH down. I've added MA three times:

    1. Just prior to the SLAM; worked exactly as PoolMath said it should (got down to 7.2 for the SLAM)
    2. After the SLAM...but I think too close to chlorinating. Had little effect (dropped between the 7.5 and 7.8 colors)
    3. Yesterday, waited over an hour after chlorinating, it had very little effect (again, slightly lower than 7.8 color to my eye)

    I'm not sure if this is a concern or just where my stasis level is for my pool but if anyone has any thoughts I'd love to hear them.

    Edit: also, since I know people on this forum love pictures, I've attached what my SLAM looked like.
    Attached Images Attached Images
    Last edited by Bender; 06-15-2014 at 12:24 PM. Reason: Add photo from SLAM
    ~12k gallon in-ground, Pebble Sheen, Hayward Pro-Grid D.E. filter, Pentair WhisperFlo, Zodiac MX8, TF-100 test kit

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