Suggested Additions To SLAM Instructions

[Chuck_Davis]

Based on personal experience, I would like to suggest two additions to the instructions for SLAMing a pool.

(Note - My water was clear - THANK YOU borates - but a newly installed Liquidator couldn't build up any level of Free Chlorine. Something was eating the chlorine.)

1) Recommend that SLAMmers open up and clean out light niches and any other places where water doesn't readily circulate.

In this thread (low-fc-can-t-figure-out-why-t66420.html), alphadog had been SLAMing his pool for 4 days without any noticeable improvement in chlorine demand. Butterfly suggested "checking out" his light niche. Techguy commented "Light niches seem to be the number one cause of long term failures of OCLT. Clean out the niche, bump your FC." As soon as alphadog opened and cleaned out his light niche, he was able to hold the SLAM chlorine level.

I had the same experience. After unsuccessfully SLAMing my pool for several days I discovered the thread referenced above. As soon as I opened the light niche and cleaned the mung out, and exposed the niche to the high FC in the pool water, I was able to successfully complete the SLAM process and use the Liquidator.

Notes - Rather than go into the pool, with its high FC, I used a toilet brush to clean out the niche. Under the heading of "can't hurt, might help" I used a funnel and a short length of garden hose to pour several gallons of bleach directly into the niche. I also poured bleach directly over the back of the light fixture.

2) SLAMing a pool may remove metal sequestrants from the water, possibly causing staining. The sequestrant level may have to be reestablished after SLAMing. It might also be best to perform a stain treatment after SLAMing a pool, rather than before.

I learned from Jack's Magic that their Blue Stuff can withstand around 10 PPM of FC for a short period, but higher FC levels, or longer periods of time, will "consume" the sequestrant. After SLAMing, the sequestrant level may have to be built back up.

Just prior to SLAMing my pool I had performed an AA stain treatment. After the AA treatment I put in 2 quarts of Blue Stuff. (this was the first time I had used Blue Stuff. The recommended amount was 1.5 quarts for my 15,000 gallon pool.) After I completed the SLAM, the metal stains started to reappear.

As part of starting to use Blue Stuff (but after the SLAM), I purchased a sequestrant test kit from LaMotte (after confirming that it would work with the sequestrant in Blue Stuff). The recommended level of sequestrant is 10-12 ppm. Despite having added (so far) 4 quarts of post-SLAM Blue Stuff, I've never been able to get above 4-5 ppm. The tech at Jack's Magic confirmed that the high FC levels of the SLAM probably "consumed" the (old and new) sequestrant, liberating the metals which were then re-deposited. He said that I wouldn't be able to get up to the 10-12 ppm level until all the now-free metals were bound up and a residual level of sequestrant could be built up. He said that this could easily take several more quarts of Blue Stuff. (I apparently have *lots* of metal in my water, and the nominal 1.5 quart recommendation, with weekly 1/4-1/3 quart additions, might have been insufficient.)

 

[duraleigh]

One of the most important concerns when we write a "how to" article is simplicity. The fewer instructions, the better newbies can follow and understand what they are doing.

Cleaning the light niche has some merit and certainly can be considered for addition. That said, many, many SLAMs are completed successfully without that step so it's sort of a toss-up as to whether to further complicate the process or not. All of our articles change and evolve over time so the addition of cleaning the niche may be in the future if we continue to notice enough SLAMs requiring that to completion.

Most pools do not have metals. Sequestering metals in a pool is really a seperate subject and not pertinent to the majority of pools. The additional complexity of addressing metals during a SLAM would really test the newly acquired skills of a beginner and should be addressed as a seperate issue, if necessary.

Your input is quite valuable as it adds to the overall knowledge level of the forum. Many readers will get value from your input and perhaps be more aware of these two possible steps they may have to perform.

 

[Patrick_B]

Dave said it better than I was thinking of putting it down. Metals are really too complex to include in a SLAM, and must be addressed separately. Glad you are enjoying the forum and it's nice to have input from different perspectives. Light Niche issues do seem to vary a lot, but it normally seems like they get down to passing or failing OCLT, and even this is marginal at times.

 

[Chuck_Davis]

I understand the K.I.S.S. Principle. I've been writing technical documentation - and struggling to make it idiot-resistant - for years.

Luckily I stumbled across the thread that (almost offhandedly) mentioned the light niche. If there are any experience-based reports or suggestions that are frequent enough to warrant citation, it would be nice to have them in proximity to the SLAM (or other standard procedure) instructions rather than trusting to luck with a Google search on the TFP site.

Perhaps you could add some links to some if/then sub-topics at the bottom of the SLAM instructions: "If you are unable to meet the criteria of Step 3 after x days", "If you use metal sequestrants", "If your water turns chartreuse", etc.

 

[Patrick_B]

Good food for thought and just know that much of the stuff in Pool School and otherwise is being updated and looked at fairly often. Some of it right now as we speak.

 

[woodyp]

I like his link suggestions. BUT........there is not one article in pool school that couldn't possibly have more links to confuse you to death too!

 

[Chuck_Davis]

And while we are weaving this tangled web...............The AA stain treatment notes could be updated to say that if you are also going to SLAM the pool, and if the moon is full, but not if it's Tuesday, to do the SLAM treatment before the AA stain treatment.

 

[jblizzle]

And while we are weaving this tangled web...............The AA stain treatment notes could be updated to say that if you are also going to SLAM the pool, and if the moon is full, but not if it's Tuesday, to do the SLAM treatment before the AA stain treatment.

:lol: that is one thing I always got confused about ... to SLAM or deal with metals first. The correct answer is to remove the algae first and then deal with the metals as I have finally leaned