SLAMming a clear pool

duraleigh

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IMHO I don’t want to barely pass, I want to pass with flying colors. Tomorrow’s test may very well pass with a perfect score due to my errors or a ever so slightly more accurate test on the 2nd attempt. But it takes a ton of work to get to that point and just a little work to let it ride for one more day so to me it’s worth it.
Admirable words and goals but that's not how it works.

Combined chloramines are an indicator of the contaminants that have bonded with chlorine in your water. That is a moving target and varies from day to day and even hour by hour depending on the contaminant input. You might work desperately to get a cc test result of 0 ppm only to find it is .5 only 10 hours later.

A CC test of 1 ppm or greater suggests increased organic activity in your pool and calls for careful testing, observation, perhaps elevated chlorine levels or perhaps even a SLAM.

TFP suggests that CC's of .5 ppm fall in the realm of normal, sanitized conditions and are treated as if they were zero
 
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Newdude

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Jun 16, 2019
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Admirable words and goals but that's not how it works.
I appreciate it but it kinda is how it works. Per the SLAM rules, a FC loss overnight of 1 PPM or less is passing. But is it really 1 PPM, or did I accidentally only use 9.8 ml of test water that sure looked like 10 ml ? Or were a few of the reagent drops slightly bigger and made the test pass? My 1 PPM loss is really a 1.1 and then fails, but is indistinguishable between the two. At a loss of 1/2 FC it can be off by a hair and .6 still passes with plenty of room to spare.

A .5 CC is 'close enough for government work'

I readily agree that im probably splitting hairs on 1 ppm passing/failing, but with all the work it takes to get a SLAM to 1ppm OCLT loss, its easy to stay the course for another day or two to remove the question from the equation. And hey, its much cheaper than going to the Dr for sleeping pills, amirite????
 

Newdude

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Jun 16, 2019
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NY
What about doing a 2nd 25ml test if you get 1PPM loss so that it’s accurate to .2 instead of .5 ? A .8 result would then give you the breathing room for all the possible variables.
 
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duraleigh

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I was only speaking to the CC test (Not FC) and I think you missed my point. The cc test may be zero one day and then .5 the next and then zero a third day and then .5 on the fourth day. That TFP calls it a pass with either .5 cc or 0.0 cc is only a guideline and attempting to get a 0.0 result each time you test is futile.

In any event, we have hijacked the thread and I am done with the subject unless you take it to PM.
 
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bmj0928

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Jun 25, 2020
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Pittsburgh, PA
Well, that was fun while it lasted. I'm super duper chlorinating at the MA level, and got a 2.5 FC loss last night, and a CC of 1.5 this morning.

It stormed a bit last night, and I ended up with another inch of water and a few leaves in the pool, but that shouldn't affect chlorine levels that much, from what I've read in the forums.

And so it goes....
 

cowboycasey

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Well, that was fun while it lasted. I'm super duper chlorinating at the MA level, and got a 2.5 FC loss last night, and a CC of 1.5 this morning.

It stormed a bit last night, and I ended up with another inch of water and a few leaves in the pool, but that shouldn't affect chlorine levels that much, from what I've read in the forums.

And so it goes....
Well whatever was hanging on your killing it now... WOW, a 1.5 cc is up there and that is actually good in your situation because you know your killing whatever was left.. Great job.... I will say that you will get a FC loss with a rain event because it is diluting your FC amount that you had before but the fact that the CC went up is the key.. :whoot:
 
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bmj0928

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Jun 25, 2020
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Pittsburgh, PA
Well whatever was hanging on your killing it now... WOW, a 1.5 cc is up there and that is actually good in your situation because you know your killing whatever was left.. Great job.... I will say that you will get a FC loss with a rain event because it is diluting your FC amount that you had before but the fact that the CC went up is the key.. :whoot:
Thanks. Perhaps this "super slam" is the finishing move I need. :)
 

bmj0928

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Jun 25, 2020
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Pittsburgh, PA
Last night I had an FC drop of 0, but a CC increase of 0.5 from 1 to 1.5.
I guess that falls within the margin of error, but with a CC of 1.5 it seems I'm still killing something.
The plan today is to wash down my cartridge filters after a brush and vacuum.
 

duraleigh

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I would suggest the FC test vial be cleaned with rubbing alcohol or a 4:1 solution of muriatic acid. Bleach could easily leave a residual that might affect the next test.
 

nabril15

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May 22, 2011
465
Miami, FL
I know that pool stores are frowned upon and avoided in the TFP world, but I suggest using Leslie's for your bleach needs next time. They have a points loyalty program that gives you a free refill after noine fills. As part of that program, they send coupons out quite often for 2 fills for $7.7 or 3 for $11, and those count towards the 9. And during a bleach, having jugs of 2.5 gallons is more convenient than gallon bottles from Walmart or wherever.

Also, definitely use 5ml for your FC tests during the slam, and buy the R0871 from Amazon or poolweb in the bigger 16 ounce bottle.
 

duraleigh

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An FC test of 5ml pool water coarsens the resolution too much (plus or minus 1 ppm) and you cannot do the SLAM as suggested by the TFP article. Everyone on this forum is free to care for their pool any way they like, but these guides are not willy-nilly made up guesswork.

Please use a 10 ml sample if you SLAM the pool. Visit the pool store at your own risk! :mrgreen: :mrgreen:
 
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bmj0928

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Jun 25, 2020
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Pittsburgh, PA
I have officially ended my SLAM on Labor Day (9/7) after I met all the criteria. A final brush, vacuum, and filter cleaning (see post above) marked the occasion. The chlorine levels are slowly coming down. I haven't had to add chlorine in 3 days.
 
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bmj0928

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Jun 25, 2020
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Pittsburgh, PA
I'm down to my normal chlorine level, and it's maintaining with no additions. I haven't added chlorine all week. After the last filter cleaning, my filter pressure has been lower than it has been all SLAM (even though it was cleaned several times during the slam). I think the SLAM made my pool trouble free!
 
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