SLAM Criteria Disagreement

Gx

LifeTime Supporter
May 17, 2013
41
Lexington, Ky
The crux of the recent replies seems to be that it takes little more LC to maintain FC at 20 than it does at 5. If this were true, I agree that it makes the most sense to just keep it at 20.

But, isn't the loss more of a percentage? Dropping 3ppm from 5 is 60%. Apply that to 20 & you're at 8, which now requires significant LC daily.
Many, if not most pools, have some tree cover. Others, like mine, do not. It is also separated from the house, so the sun has little impediment.

So, this seems to boil down to just the safety of maintaining SLAM, vs _perhaps_ saving $$ & time by letting FC drop after repeatedly passing OCLT & CC tests.

If you've not experienced it, with a fairly large pool, you may not appreciate the time/trouble/expense of maintaining FC 20 for weeks.
And you never know how much LC to purchase, as you don't know how many more days you have to go. Especially given shortages, this is also a non-trivial issue.
 

Mdragger88

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Jun 1, 2018
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Usually we find that if you’re taking weeks to clear after passing oclt’s there’s a reason. Hidden algae in light niches, skimmer weirs, drain covers, water features, heaters etc. or possibly a filtering issue that needs to be addressed.
 
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Newdude

Gold Supporter
TFP Guide
Jun 16, 2019
10,374
NY
Reason # 1 to SLAM is obviously because it works for anybody, anywhere in the world.

Reason # 2 is when somebody sees firsthand exactly how hard it is to undo those problems, once and for all, and not the yo-yo pool store way.......... they will be extra vigilant about their upkeep maintenance from then on.
So it’s a twofold lesson. How to clear it, and why they only want to do it once.

‘Oh but Newdude it’s every spring and not during the swim season’.

I hear you. Change your winter approach.
 
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skimmerswimmer

Well-known member
Jul 30, 2013
474
Long Island, NY
Reason # 1 to SLAM is obviously because it works for anybody, anywhere in the world.

Reason # 2 is when somebody sees firsthand exactly how hard it is to undo those problems, once and for all, and not the yo-yo pool store way.......... they will be extra vigilant about their upkeep maintenance from then on.
So it’s a twofold lesson. How to clear it, and why they only want to do it once.

‘Oh but Newdude it’s every spring and not during the swim season’.

I hear you. Change your winter approach.
^ x 1000%
Once I started closing late in the season and opening early, in addition to keeping a high FC at closing, dropping in the robot a few times over the winter to pick up newly blown in leaves, and keeping two floaters suspended in the middle of the pool on a line with 3 pucks each for residual chlorine over the winter, I have never opened to a green pool...always crystal clear.
 
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Katodude

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Aug 22, 2017
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So one of the hardest things I had to learn and accept is this is not a forum to discuss and talk about different forms of pool management. There is an approach that is the approach this site espouses, it is the TFP method. It is fairly rigid but has some wiggle room. As @Newdude said earlier it work with everyone everywhere. It is based on the experience of thousands of pools and hard science.

While other methods may work that is not what we do here. Once you accept that, this becomes much easier. I know it sounds cultish but its not. Its a method for pools. That simple. The people are friendly and here to help without any expectation of renumeration. They will help you with your issues and give you correct guidance on the approach. Like I suggested earlier you might have to get creative to find LC but I promise you will find as much as you need within a reasonable distance from where you live. You might just have to look a little harder than normal.

I have made many virtual friends here shared some of my knowledge and shipped spare parts to other members that I just had some extra of. I have gotten much more than I have given.

Talk about you ideas and continue to ask your questions. But unless you have some hard science, where you can convince the people here that are much smarter than you and me combined on pools, you wont get them to change the approach just because it is a little hard for you during these unique times.
 

Leebo

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You are 100% correct, you will see a larger drop in FC at higher levels. That said, it’s a trade-off, speed or cost. It’s gonna be faster at higher levels as theres more chlorine there to break everything down and help the filter do it’s job. Also don’t forget using your example the users is only gonna use an extra 4 ppm per day, for a 20,000 gallon pool we’re talking like $3 extra, even during the shortage.
 

TexEdmond

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Jun 16, 2021
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Just because people weren't giving your post the respect and time you feel it deserved doesn't mean the forum is a cult.

If you happen to have copper algaecide in your pool, we literally recommend frequently dabbling in OC-Cu-LT practices though...
 

TexEdmond

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Jun 16, 2021
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I wonder if you realize that your T-15 SWG cell is undersized for your big pool? This may be the crux of your problem.

Whether or not the user has a SWG on their pool is irrelevant to the SLAM discussion, because the SLAM recommendations are to turn the SWG off entirely. I know squat about slamming but this really makes no sense to me, after reading on this same website that "pools with SWG tend to stay algae free at lower FC levels."


But unless you have some hard science, where you can convince the people here that are much smarter than you and me combined on pools, you wont get them to change the approach

This website and its attached calculators and apps should have ample data to analyze to do exactly that hard science, so it's not fair to put the burden of that on someone who doesn't have access to the data... And if the website doesn't already have one, they should immediately employ a data analytics team. It's quite possible that our fellowship of pool owners is the largest and most accurate real-time repository of data on pools that has ever existed.
 

magiteck

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May 20, 2020
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This website and its attached calculators and apps should have ample data to analyze to do exactly that hard science, so it's not fair to put the burden of that on someone who doesn't have access to the data... And if the website doesn't already have one, they should immediately employ a data analytics team. It's quite possible that our fellowship of pool owners is the largest and most accurate real-time repository of data on pools that has ever existed.
Subjective water clarity is not a metric tracked in PoolMath so there is no analytics one could do to identify users who stopped their SLAM when all criteria except water clarity were met.

TFPC is an established scientific theory. The onus should be on the individual(s) proposing to change an aspect of that theory to prove that the change can yield comparable results. The TFPC community does not need to “re-prove” whether or not removing one of the current criteria could yield similar results. I don’t believe that would be an efficient use of volunteer resources.
 

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Selenap

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May 28, 2021
235
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If you have a bacterial infection, you’re prescribed antibiotics with instructions to take at regular intervals and complete the full course. You can quit taking them when you feel better and hopefully you took enough. Or, a week goes by after stopping short of taking the full prescription and boom! You get even sicker with the bacteria that survived, mutated and grew stronger, leading to needing a stronger dose of antibiotics. Maybe it’s the same idea for algae.
 

TexEdmond

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Jun 16, 2021
418
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TFPC is an established scientific theory. The onus should be on the individual(s) proposing to change an aspect of that theory to prove that the change can yield comparable results.

A scientific theory that's based 33% on a subjective measurement in this SLAM instance? Shall we stop the discussion there? Certainly there is some way to measure water clarity, even if it's as simple as putting a black dot on the end of a pool pole and lowering it into the deep end same as the CYA test until it disappears.

The TFPC community does not need to “re-prove” whether or not removing one of the current criteria could yield similar results

Maybe? Maybe not. Maybe that's not what's being asked. It seems wise to re-evaluate and optimize, to consider differing viewpoints and differing opinions. It seems anti-scientific to dismiss obvious measured data or legitimate questions that falsify the theory. Science is based on continually re-proving, testing, sharing information, optimizing, keeping an open mind (which I seem to remember being a big guideline at this website).

For example: The criteria to exit a SLAM are two chemically measureable levels, and one subjective one, water clarity. Water clarity can be affected by both biological and chemical factors. It's easy to imagine doing everything recommended in a SLAM, and in the days / weeks that followed, the CSI of the pool creeps up to a point where calcium begins to come out of solution. The SLAM criteria says, "Cloudy Pool? Keep on Slamming" without acknowledging that chlorine might not fix the problem.

While I don't share their viewpoint, it makes sense that someone might consider rigidity to asking questions or changing methods as "cultist." Maybe it's just "dogmatic?" It also makes total sense that everyday pool owners come to the experts on this site with old habits and frankly, snake oil, and that's got to be frustrating as heck to answer those same questions over and over and over again, just to see the pool owner come back next year with the same problems. It'd be easy to dismiss any method that "strays from the path" or an attempt to learn more about how those methods were created and say, "Welp, you didn't do exactly this, so you're hosed."

Subjective water clarity is not a metric tracked in PoolMath so there is no analytics one could do

Can you help me understand how you know this to be true? Data analytics engineers are continually seeking to identify hidden, untracked metrics like this. (source: I sleep next to one every night)

Maybe it’s the same idea for algae.

It's my understanding after reading here that yellow algae is significantly more chlorine resistant than green algae. Also cryptosporidium poo bacteria. Nasty stuff.
 
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skimmerswimmer

Well-known member
Jul 30, 2013
474
Long Island, NY
The SLAM article simply states "the water is clear" as a pass criteria. This would be a subjective characteristic based on the pool owner's experience with their own water history and system. So the question is not "how clear" but "what is clear to you". If my pool was not as clear as I'm used to seeing it, then I either have a filtration problem or I have a chlorination problem. If I take my filter apart to check for issues and I find none, then I either have to wait until enough time has passed to filter out the remaining particulates that are making the pool "less clear than normal", or I need to wait until enough time has passed for the chlorine to do it's job. In either case, my SLAM is not complete...in my eyes. Everyone needs to figure out their own level of "it's clear." I have a quad DE filter, so obviously my water is going to end up being clearer than someone with a sand filter.
 

AK-

Gold Supporter
May 11, 2021
367
Randolph, NJ
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There may be subjective levels of clear, but cloudy water is clearly not clear water and the same is true for water with visible patches of algae.

Keep in mind that when all 3 SLAM stop criteria is met your FC level will slowly drop from SLAM to target (hopefully you will maintain it at target level), which alone should kill any residual algae (or other organisms in the water) and that makes the point on water clearness being subjective moot.
Doesn't really matter if the water is clear to one person, but not clear enough to another. The chlorine will sanitize it anyway. If the water is cloudy or has large particles in suspension then you might still have "stuff" in the water you want removed as fast as possible.

We can go as far as saying SLAM is "not absolutely" necessary to turn a green pool into a clear pool. If you manage to keep your FC at target levels all the times and filter/vacuum it enough it will clear up. It may take several months, but eventually it will clear up.
SLAM is just the tested and proven way to quickly clear a pool without damaging the pool or pool equipment.
 
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Katodude

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Aug 22, 2017
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We can go as far as saying SLAM is "not absolutely" necessary to turn a green pool into a clear pool. If you manage to keep your FC at target levels all the times and filter/vacuum it enough it will clear up. It may take several months, but eventually it will clear up.

I think the issue is this is not really practical. Keeping your FC at target levels gets MUCH harder when you have algae. It would mean measuring and dosing several times a day for months.
 
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AK-

Gold Supporter
May 11, 2021
367
Randolph, NJ
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I think the issue is this is not really practical. Keeping your FC at target levels gets MUCH harder when you have algae. It would mean measuring and dosing several times a day for months.
Yeap. It is definitively not practical, but not impossible. It will likely lead to some sort of psychological or psychiatric breakdown before achieving clear water. Filling the pool with dirt is another way to get rid of algae (and the pool).

My point is one does not have to follow SLAM to clean a pool. But SLAM it is a sure way to do so that was tested over and over and proven to work.... The clearness of the water is secondary to not visibly have nasties in the water.
 

cledee

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A scientific theory that's based 33% on a subjective measurement in this SLAM instance? Shall we stop the discussion there? Certainly there is some way to measure water clarity, even if it's as simple as putting a black dot on the end of a pool pole and lowering it into the deep end same as the CYA test until it disappears.



Maybe? Maybe not. Maybe that's not what's being asked. It seems wise to re-evaluate and optimize, to consider differing viewpoints and differing opinions. It seems anti-scientific to dismiss obvious measured data or legitimate questions that falsify the theory. Science is based on continually re-proving, testing, sharing information, optimizing, keeping an open mind (which I seem to remember being a big guideline at this website).

For example: The criteria to exit a SLAM are two chemically measureable levels, and one subjective one, water clarity. Water clarity can be affected by both biological and chemical factors. It's easy to imagine doing everything recommended in a SLAM, and in the days / weeks that followed, the CSI of the pool creeps up to a point where calcium begins to come out of solution. The SLAM criteria says, "Cloudy Pool? Keep on Slamming" without acknowledging that chlorine might not fix the problem.

While I don't share their viewpoint, it makes sense that someone might consider rigidity to asking questions or changing methods as "cultist." Maybe it's just "dogmatic?" It also makes total sense that everyday pool owners come to the experts on this site with old habits and frankly, snake oil, and that's got to be frustrating as heck to answer those same questions over and over and over again, just to see the pool owner come back next year with the same problems. It'd be easy to dismiss any method that "strays from the path" or an attempt to learn more about how those methods were created and say, "Welp, you didn't do exactly this, so you're hosed."



Can you help me understand how you know this to be true? Data analytics engineers are continually seeking to identify hidden, untracked metrics like this. (source: I sleep next to one every night)



It's my understanding after reading here that yellow algae is significantly more chlorine resistant than green algae. Also cryptosporidium poo bacteria. Nasty stuff.
Cloudy water can only be caused by two things. Algae or having high PH. High PH alone won't cause cloudy water but it's a big contributing factor. Having high Calcium is also problematic but if your PH is in line it should not be an issue.
If your testing regularly, then that's why if you have cloudy water it states to keep slamming, as it could only be algae since you would have already known if anything else was off.
 

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