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Thread: First Attempt at SLAM procedure

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    First Attempt at SLAM procedure

    Warning: First post by pool newbie

    This is my family's first year in a new home that has a pool. Prior to this home, I've never had any experience with a pool. I've been following TFP since early Spring and am grateful for all the advice I've garnered from the forum, and have been managing/learning our pool by the TFP method.

    Bought the house during the winter, and although we had a "pool inspection," prior to purchase, the inspection failed to uncover a number of issues with the pool, but thanks to the TFP forum, I have acquired a not-so-expensive education.

    As stated, I've been managing the pool by the TFP method, following recommended guidelines on chemistry, and using a TF-test kit to monitor. Up until the past 1 1/2 weeks my numbers routinely were:

    pH: between 7.5 and 7.8
    TA: 65-70
    CH: 125
    CYA: 65(ish) normally but in past week or so has gone down to 40-50.
    Salt: 3200-3400
    FC: 3.5-5.5, usually around 4.5
    CC: Has always been 0, since I started testing with TF-Test Kit in April.

    Other background info: I have added DE to my sand filter per the Pool School directions. To the best of my knowledge and research the sand in my filter has never been changed since the pool was install in 2008. I discovered that the motherboard on my AquaLogic had the "No Cell Power" issue which I fixed for $5 thanks to info on this forum (No idea how long the Salt cell could have been non-functional). I think I have a slow leak somewhere, but have yet to determine where.

    Up until this past weekend, I felt that there was no obvious sign that I needed to shock my pool. My chemistry always fell in line with recommendations, and I managed additions and adjustments using Pool Math. As stated above, my CC has always been 0. This past weekend, however, we had a "poop in the pool" emergency thanks to a friend's 3yo sans swim diaper. I headed to the TFP forum to find out what the recommendations are, and proceeded to begin my first SLAM the following day.

    Day 1: Outside temp 90+ degrees and sunny. Started by adding bleach (around 2:00 PM) to bring FC up to 27.0 ppm. After 1.5 hours the FC had dropped to 25.0. After three hours FC was at 20.0 ppm. Water was clear and CC was (as always) 0. Decided to perform OCLT. First reading was 18.0, then morning reading was 15.5, thus a 2.5 overnight Cl loss. I know this means keep slamming.

    My weekday schedule makes it difficult to be there during the day to measure and dose to maintain FC above shock level. I think the sun is inactivating the Cl more than residual organics, though from the OCLT there obviously is some organics still in there somewhere.

    1) If I wait and dose at dark, remeasure at dawn, with no maintenance doses during the day, will a subsequent OCLT be undermined? Am I "spinning my wheels?"

    2) Does dosing above and beyond the shock level (to compensate for FC falling when I can't be there to re-dose) run any risk of equipment damage or other problems?

    3) Does dosing above shock target accelerate the SLAM?

    If I seem to be missing something, I'm very interested to learn. THANKS!
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
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    Re: First Attempt at SLAM procedure

    Welcome to TFP!!!

    Thanks for reading and getting a test kit before posting

    1) Not sure I understand. You need to do a measurement in the evening (at least 30 minutes after the last chlorine dose) and a measurement in the morning with no FC additions between them for a valid OCLT.

    2) Yes, you put yourself at risk for fading the liner. Never raise the FC above mustard shock level for your CYA. Best to just try to maintain the shock FC level as best you can. You should be able test and dose at least 3 times, once in the morning, once when you get home, and once before bed.

    3) It will speed up killing what ever is in the pool, but put yourself at risk, see #2.
    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
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  3. Back To Top    #3

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    Re: First Attempt at SLAM procedure

    My issue is I started slamming on Sunday afternoon. I did the OCLT that evening just to see if the pool might pass. I was actually surprised when I didn't since I've been going on the assumption that with CC at 0, there was no need to SLAM.

    I work long hours and my only chance at dosing during the weekday would be before dawn and then once more at dusk. I'm concerned with sun exposure during the day I lose Shock level FC, then even with a dose at dusk, I still haven't held SHOCK level long enough prior during the day to complete the process. I suppose this is my first trial and error run through on the SLAM procedure. Will see in the morning, I brought up to near mustard shock tonight. Will check in the AM. I guess there's a chance with high FC in the morning it still might hold above Shock FC even drifting downward during the day.

    Coincidentally, any thoughts on what or where the organics could be hiding? The water is clear and CC is still 0. The pool liner is the cleanest it's ever been. Could it be the filter? Will Slamming clean the filter?
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

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    Re: First Attempt at SLAM procedure

    Welcome fellow Georg`n.
    Congrats on finding TFPC on Your 1st pool. It took me 15+yrs to learn better.(a lot of wasted money)
    This site is awesome
    35900 inground, 1 1/2 hp superpump, Jacuzzi sand filter, barracuda 3 cleaner

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    Re: First Attempt at SLAM procedure

    Very glad to be here. I preach the good news about this forum nearly every day. I can assign probably $2000+ in savings this year to info garnered from TFP. And I feel empowered because I'm learning the why, not just the what and how. It has made owning a pool so much less intimidating.
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

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    Butterfly's Avatar
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    Re: First Attempt at SLAM procedure

    Quote Originally Posted by lazybonz View Post
    Very glad to be here. I preach the good news about this forum nearly every day. I can assign probably $2000+ in savings this year to info garnered from TFP. And I feel empowered because I'm learning the why, not just the what and how. It has made owning a pool so much less intimidating.
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ One should not use a sledge hammer to swat a mosquito. ~

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    Mod Squad jblizzle's Avatar
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    Re: First Attempt at SLAM procedure

    Well, with $2000 in savings, Becoming a TFP Supporter is chump change
    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!

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    Re: First Attempt at SLAM procedure

    Quote Originally Posted by jblizzle View Post
    Well, with $2000 in savings, Becoming a TFP Supporter is chump change
    @jblizzle: How bout them apples!?

    So, I'm still a lesson in progress on the SLAM - learning how to perform the procedure and that there are "secrets" about my pool I may not yet know. First OCLT came in at 2.5 ppm loss; second(after bringing FC to mustard shock level) was 2.0. The water is crystal clear and my CC is still 0. I have company coming this weekend and we have two days of blazing hot sunny skies ahead, so for the time I'm aborting the SLAM and will come back to it again when I have several days available when no pool use is expected. It seems I lose about 10-12ppm a day (with SWCG off) from sun exposure, so I figure the pool should be OK for rugrats by late Thursday afternoon.

    Still a little puzzled by the SLAM. My water has always been clear (though not quite as clear as it is now) and my CC has always been 0. Other than on the behalf of the poop fiasco, how would I have ever known that my pool needed a slam? Obviously by the SLAM criteria and failing two OCLT's something else has been there all along? I'm still suspicious of what may be going on in my filter. After 6 mos in this new house, I'm learning that the previous homeowners were not big on general preventive maintenance. I suppose this fall, I may crack the filter open and investigate. Could the filter hold enough biofilm that it would take days at shock to neutralize it?
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

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    Richard320's Avatar
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    Re: First Attempt at SLAM procedure

    Quote Originally Posted by lazybonz View Post
    Still a little puzzled by the SLAM. My water has always been clear (though not quite as clear as it is now) and my CC has always been 0. Other than on the behalf of the poop fiasco, how would I have ever known that my pool needed a slam? Obviously by the SLAM criteria and failing two OCLT's something else has been there all along? I'm still suspicious of what may be going on in my filter. After 6 mos in this new house, I'm learning that the previous homeowners were not big on general preventive maintenance. I suppose this fall, I may crack the filter open and investigate. Could the filter hold enough biofilm that it would take days at shock to neutralize it?
    Doesn't have to be biofilm - it could just be a lot of organics. Chlorine is an oxidizer - flameless burning. It could just be trying to burn up a bunch of lead crumbs and dead insects trapped in the sand. Why not crack it open now and do a deep cleaning?
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: First Attempt at SLAM procedure

    its probably overkill, but if I bought a house with a pool, with a sandfilter.... as cheap as sand is, I would probably replace it anyway, just to start fresh. btw, filter sand makes excellent "fill in" for any small low areas or holes in your yard. When I took down our old intex this year in favor of our new pool, I dumped the sand into a hole our boxer dug near the back porch. the bermuda grass took it over and you would never know a hole was ever there....
    Partially buried Doughboy Desert Spring 16 x 32, sport pool, with 7 ft deep middle, 20,000 gallons, Hayward Powerflo Matrix 1.5 HP 2 speed pump, 250 lb sandfilter, 2 Doughboy skimmers and 2 returns. 2 cascade fountains.
    Taylor K-2006 kit. Zodiac Barracuda Ranger suction side cleaner.
    TFPC method and is crystal clear every day thanks to TFP!!!

  11. Back To Top    #11

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    Re: First Attempt at SLAM procedure

    I do plan to service the filter in the fall, but for now, my I have a tough time telling my kids they can't swim when the water is still clear and the tests are in range. I'll let them enjoy it to the max this season, and address it if and when it becomes an insurmountable problem.

    I've been bouncing around the forum trying to read up on SLAM. The three criteria for the completion of a SLAM are clear water, CC<0.5ppm, and OCLT<1.0ppm. I have been following the recommendations, OTO test a few times a week, complete set of tests on the weekend, but I haven't been performing the OCLT on any frequency because my water has been clear and CC have always been 0. What is the forum recommendation on when to perform an OCLT outside of the SLAM procedure? I don't think I would have ever had a clue that some organic load was being sustained without doing the OCLT. Should that be part of the weekly regimen also?
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

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    Re: First Attempt at SLAM procedure

    @Richard320: A lot I have read on here mentions that the SLAM procedure can take days and days. One post I read stated the user needed over 90 jugs of bleach and ten days time to pass an OCLT. The only place I can think of organic material residing in my system is in my filter. Wouldn't it be cheaper and less time consuming to deep clean the filter before trying to SLAM? It's kind of like an infection. Why deal with it over two weeks on antibiotics, when it can be removed at once surgically. I know that's a little over simplified.
    IGVL (Liner ~10 yrs old), 25,000 gal (18x36 ft, 8 ft deep end), 2 drains, 3 returns + Polaris return, 2 Hayward skimmers, AquaLogic Control Unit, T-15 Salt cell, Hayward Super Pump 1 hp, Polaris Pressure Cleaner (280) w/ Booster Pump, Hayward S244T Sand Filter, TFPC method with TF-100 Test Kit + Speedstir

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    Re: First Attempt at SLAM procedure

    Quote Originally Posted by lazybonz View Post
    @Richard320: A lot I have read on here mentions that the SLAM procedure can take days and days. One post I read stated the user needed over 90 jugs of bleach and ten days time to pass an OCLT. The only place I can think of organic material residing in my system is in my filter. Wouldn't it be cheaper and less time consuming to deep clean the filter before trying to SLAM? It's kind of like an infection. Why deal with it over two weeks on antibiotics, when it can be removed at once surgically. I know that's a little over simplified.
    Open it up and see!
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    jtaves85mcss's Avatar
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    Re: First Attempt at SLAM procedure

    Welcome to the forums.

    I have no experience with SWGs, but I'm a little puzzled by info in posts 1, 8 and 11. Most likely my confusion is related to use, failure of the SWG and possibly shutting it off for the SLAM. I'll offer a few questions and suggestions that may help. Sorry to hear you have gotten into the algae problem.

    In #1 notes "FC: 3.5-5.5, usually around 4.5" and "I discovered that the motherboard on my AquaLogic had the "No Cell Power" issue which I fixed for $5 thanks to info on this forum (No idea how long the Salt cell could have been non-functional). "

    How long the SWG was not operating is not the biggest issue as compared to what the FC level was when it was repaired. If you opened to FC=0 or found the SWG off and FC = 0 was an indicator to start the SLAM and conduct OCLT.


    In #8 notes "It seems I lose about 10-12ppm a day (with SWCG off) from sun exposure, ...."

    I'll assume this loss was happening when trying to conduct SLAM at higher FC level and there was not an expectation that the SWG generate 10ppm over the day. You should note this loss is not just due to the sun, but includes whatever is growing in the pool. Being able to conduct a series of FC tests and Cl additions over 4 or 5 hours would really give you an idea of amount being used to kill the crud. Typical loss in my CYA=30 pool is approximately 2 ppm per day.

    In #11 notes "I have been following the recommendations, OTO test a few times a week, complete set of tests on the weekend, ..."

    I have no idea whether a SWG allows you to do testing less frequently, but my suggestion would be to test daily and at least make sure SWG is running every day.

    I hope you get a few hours this holiday weekend to further investigate the issue, but most importantly enjoy the company.
    Pool: IG 22k- 16x32 clipped corners- vinyl liner, w/ a great board. Built in 3/99, new to me 2/2011.
    Equip: Hayward 3600 DE filter, Hayward CL-200 Chlorinator (empty since 7/5/2013).
    K-2006 Test kit with Speedstir
    Located in Cincinnati, OH. TFP lurker since 9/2011, BBB interested since 5/2012 and converted 7/2013.

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