Role of SWCG in SLAM

nutria

LifeTime Supporter
Feb 20, 2015
50
Austin, TX
Hi everybody,
I have been following the methods here (with liquid chlorine) for about a year with reasonable success. I just installed a SWCG this weekend to avoid having to carry chlorine around all the time and now I am in the middle of a SLAM due to my inconsistent chlorinating schedule previously. My question is: why is it recommended here NOT to use the SWCG at all during a SLAM? I get that you don't want to use it to reach the shock level, but why not use it for the "maintain" part of the SLAM? I am one of those who cannot be at the side of the pool during a normal workday and it seems like the SWCG could really help in keeping those FC levels up while I am away and until I am ready to put in more of the liquid stuff. This is especially true if the SWCG is oversized as recommended here.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
You can certainly use the SWG to help maintain your FC level if you are not around.

A couple reasons we usually recommend not to:
1. You get a better feel for the process when you can see the rate of FC consumption dropping as the SLAM continues. You have less of a feel for this when the SWG is adding FC.
2. The SWG MUST be off when you try the OCLT.
3. Just saves a little wear and tear on the SWG cell.
 

nutria

LifeTime Supporter
Feb 20, 2015
50
Austin, TX
Thanks for the clarification! I like to understand the rationale behind the recommendations and I couldn't quite figure out why not use the newly installed chlorine factory that I have :)

So, if I understand your point, the recommendation is mostly a matter of knowing what is going on. You get a better feel for how fast chlorine is being consumed if you add everything manually and of course you don't want any chlorine production while you are doing the overnight test. About the last point, the wear and tear in the cell, isn't the cell just a way to produce chlorine? Over its lifetime time it can produce X pounds of the stuff and the usual argument is that with a SWCG you pay upfront for the chemicals, but that the cost for them over the lifetime of the system is about the same. So then, why would it matter if you are using the chlorine for a slam or just for routine levels? Is it more strain on the cell to be on 100% for the few days that the slam lasts?

You can certainly use the SWG to help maintain your FC level if you are not around.

A couple reasons we usually recommend not to:
1. You get a better feel for the process when you can see the rate of FC consumption dropping as the SLAM continues. You have less of a feel for this when the SWG is adding FC.
2. The SWG MUST be off when you try the OCLT.
3. Just saves a little wear and tear on the SWG cell.
 

AimeeH

LifeTime Supporter
TFP Guide
Apr 2, 2012
2,028
Columbia SC
Yes.

You really (I suppose) want your SWG to last as long as possible. But with that said, they produce chlorine for a finite number of hours really. If slamming, and you can't be there to add chlorine every hour or couple of hours it probably is no harm no foul to use the SWG to maintain chlorine while you're gone. I personally wouldn't reccoment the 100% setting for your SWG as that will tax it in terms of life span.

Slam with chlorine if you can. Use SWG if you must while gone. But know what you're putting in and why.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,260
Tucson, AZ
Ok, you caught me, #3 was a bit of a stretch.

You are right that the SWG will produce X amount of chlorine in its life. Running at 100% should not be any extra strain. But by running at 100% for a few days/week you have lessened the time until you need to by a new cell ... by a couple days ... I did say "a little wear and tear" :mrgreen:
 

nutria

LifeTime Supporter
Feb 20, 2015
50
Austin, TX
Thanks AimeeH and jblizzle! Makes a lot more sense now. I will continue my slam with the help of the SWCG without feeling guilty about it. I really love that thing. I was so tired of constantly buying bleach and being a member of the honor club of white speckled clothes people :)
 

pooldv

Mod Squad
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Platinum Supporter
LifeTime Supporter
Aug 10, 2012
25,408
FL panhandle
LOL! Nice! Everyone needs at least one bleach speckled shirt! Do ya'll have nutria in Austin? Or are you from New Orleans?
 

duraleigh

Admin
Mod Squad
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LifeTime Supporter
In The Industry
Apr 1, 2007
32,844
Sebring, Florida
I'll add another factor for not using the SWG for a SLAM. The very word "SLAM" means you take the FC right to the calculated level immediately. You "jolt" the FC in your pool to get it started immediately.....I'm sure the word "shock" was based on the same idea.

I can't explain this with solid science but it seem very logical to me to hit the FC very hard. I believe it will lessen the length of the SLAM.

Of course, you cannot do that with an SWG.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
3,436
Fletcher, OK
I would do exactly as we have always said, SLAM to your CYA/FC amount like Dave said "jolt". then turn on your SWG while you are away, when you return, see where you are at and using bleach bring back to SLAM level

And repeat

best of both worlds :)
 

nutria

LifeTime Supporter
Feb 20, 2015
50
Austin, TX
Yes, you would bring the level up with addition on liquid chlorine as taught here, but why not keep the SWCG on so that the level does not drop below shock (or at least not as fast)? That was all I was wondering.

I'll add another factor for not using the SWG for a SLAM. The very word "SLAM" means you take the FC right to the calculated level immediately. You "jolt" the FC in your pool to get it started immediately.....I'm sure the word "shock" was based on the same idea.

I can't explain this with solid science but it seem very logical to me to hit the FC very hard. I believe it will lessen the length of the SLAM.

Of course, you cannot do that with an SWG.
I would do exactly as we have always said, SLAM to your CYA/FC amount like Dave said "jolt". then turn on your SWG while you are away, when you return, see where you are at and using bleach bring back to SLAM level

And repeat

best of both worlds :)
Sounds sensible to me!
 

duraleigh

Admin
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In The Industry
Apr 1, 2007
32,844
Sebring, Florida
Yes, you would bring the level up with addition on liquid chlorine as taught here, but why not keep the SWCG on so that the level does not drop below shock (or at least not as fast)? That was all I was wondering.
If you do so, you cannot track your chlorine loss during the SLAM and that is important.

Review the SLAM procedures and you will see the SWG will only confuse your testing.