Facts Hard to Come by on SWG vs. Directly Chlorinated Pools

pennstump

New member
Mar 10, 2021
1
SoCal Coastal
Hi. Longtime lurker and user of the TFP method on my 45-year old, directly chlorinated pool. I bought the house 3.5 years ago and I'm looking to resurface, replumb, and update the hardware. I'm in coastal Southern California and I had always assumed that I would go SWG, but what the local pool builders have told me has caused me to re-think that.

I've had 6 bids and they came in with 3 who said they will only install SWG pools and the other 3 said they will do either but they highly recommend direct chlorine via liquid or pucks. I am planning to use a pool service, at least to start, but I might pick it back up down the road. The builder I like the best and who seemed to be the most knowledgeable (he was the owner of a 25-year pool builder) said he'll do a SWG if I twisted his arm, but he'd rather not. He said he used to do them extensively in 2005-2012, but that many of those systems either rotted out due to metal fatigue from poor maintenance or the owners chose to switch to directly chlorinated due to various reasons. He does not directly service pools or sell maintenance materials, so that's what made me start to believe him. His main reasoning was that, according to him, there were 80+ pool guys in the area that he could recommend that would do a great job keeping our pool clean with direct chlorine methods, but only 6-7 who could do a great job at maintaining a SWG pool and they are all fully-booked all of the time. He said if they work on a neighbor's pool, they might squeeze us in, but otherwise we'd have to go with someone who doesn't do a great job at adequately maintaining the pH levels with muriatic acid and that will lead to corrosion.

He also gave me some other reasons that seem to pan out by Googling: SWG pools start with an already high dissolved solids number that make balancing difficult, chronically high pH, instead of dumping liquid chlorine I may be dumping the same amount of muriatic acid weekly, pool decking may not last as long, SWGs rarely last more than 3 years, and pool equipment will last 30-50% less time. His only gripe about directly-chlorinated was high CYA levels from pucks. I asked about the salt water feel on your skin and he said from his experience only some people with sensitive skin will notice it, but that's really more about a well-cared for pool than salt vs. direct chlorine.

Here are some facts I've gathered about my area: We apparently have some of the hardest water in the country at ~245ppm on average. Pools are year-round here, but the water temp in January can reach 55F even with a spa used occasionally. Around 2010, pools in my area were being built 90% SWG and 10% direct chlorine. Now, per all of the builders it's about 60% SWG and 40% direct chlorine. Water is very expensive here, as is electricity. Partial dumps and refills are highly frowned upon during droughts, which are pretty much always here. Few trees, high sun.

Sorry for going on so long, but after searching this site and most of the Internet it seems like people are in 1 of 2 camps: pro-SWG and it's a personal preference. No one really seems to be "always direct chlorination," but some are "never SWG." This makes it really hard to make a decision since it seems like everyone has their own opinions, but facts are hard to come by. I'm really more concerned about the water quality on skin and the longevity of the pool and equipment. I figure the maintenance costs will even out otherwise.

Has anyone here every had both or converted from one to the other so they can offer some direct experience between the water feel between the 2 and the maintenance?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
21,233
Bedford, TX
Penn,

Your "trusted" pool builder is just full of Bull Feathers. I also suspect that he believes the moon is made of cheese as that is what his grandmother told him when he was 6 years old.. :mrgreen:

I have three saltwater pools.. Two of them were "puck" chlorinated pools when I bought them.. They have since been converted over to Saltwater pools, making my life has been so much easier.

In total, the pools have been saltwater for over 20 years of operating time.. I have had zero problems. As your builder points out, salt cells do not last forever.. I just replaced two of the original cells, one was over 8 years old, and the other was about 7 years old.. A cell costs about the same amount you would need to pay for 5 years of Liquid Chlorine or pucks..

The main problem with saltwater pools is that they are so easy to take care of that often people think that they do not have to test or keep their pool water balanced, which is just not true.

When you get out of a standard chlorine pool, you often feel like you need to take a shower, when you get out of a saltwater pool, you feel like you just took a shower.

You might say that I have no "proof" of my facts.. but then neither does your pool builder... :mrgreen:

Thanks,

Jim R.
 

rstrouse

Well-known member
Jun 17, 2020
83
California
For me, I choose salt water pools. Many years ago in the late 80s I had my first salt water pool. When the chlorine generator worked it was magical and easy to maintain. However, that system was a pioneer called Kreepy Clear. There was a cell mounted to the inside of the pool and a power transformer mounted at the pad. During the first couple of years it worked great but started falling apart after that. As a result I went another 15 years of manual chlorination and floaters with pucks. I often found myself out of town or busy so the only way to keep it looking good was pucks and shock. Of course after having to drain huge amounts of water off a 40,000gal pool multiple times to get CYA under control (can't imaging creating a wave in the street in California these days), I longed for the salt water pool.

When I put in the pool at my current residence I insisted on a salt system. I got all kinds of "use chlorine" advice from pool builders but I wanted to get back to the two years in the beginning that were bliss. So in 2009 I had my current pool built. It uses an IC-40 and the pool is right at the max capacity of the cell weighing in at 36kgal but it does a remarkable job and I run it at 75-80% all summer. I was told the cell would only last a few years and would need to be replaced. The punch line is that I am still using that original cell and it still works its magic. I can go out of town without expecting pea soup and it always look blue and clear. As for pH sure I add acid every couple of weeks but I am in the process of mitigating that with my own home built pH controller. By the way my deck, coping, and wall tiles are travertine and there is no salt damage to it despite the claims that there would be 11 years ago.
 
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sacredcow

Silver Supporter
May 8, 2018
155
Houston, TX
Has anyone here every had both or converted from one to the other so they can offer some direct experience between the water feel between the 2 and the maintenance?

I'm taking the leap of faith and having mine converted on Friday. I've been in both SWG and direct chlorinated pools and I honestly don't find there to be that much of a difference if they're equally well-managed.

During the Texas deep freeze, my tablet feeder exploded and I've been thinking about doing this for a while so I'm assuming that was fate telling me what to do. I have had MANY people tell me that I'm crazy and heard a number of horror stories of their problems with SWG, but none of it seems to add up. One friend said he went through cells at the rate of every 6 months, but then tells me that he recently fired his pool guy because he found out that he hadn't actually cleaned the cartridge filter in so long that his pressure was crazy high and flow crazy low. As mentioned above, I think the SWG's were often marketed as "set it and forget it," which isn't entirely true. I've been in the industrial water treatment business for 20 years, and bodies of water are nothing if not dynamic. Any system we treat (boilers, cooling towers, refinery overheads) are tested daily and adjustments are made. In short- my research indicates that the main problems people have with SWG's are due to them having the impression that they are "hands-off."

That's my $0.02. The gurus here at TFP haven't steered me wrong yet, so I'm not expecting the swap to SWG to be a problem. If I have to eat crow with my naysayer friends, I'll be sure to pack some in dry ice to share with them, though. LOL
 

Rancho Cost-a-Lotta

Silver Supporter
Apr 10, 2018
1,936
Rancho Cucamonga, CA
If you've done any googling on TFP, you've probably found that TFP supports the use of SWGs. For the three years I've been on the site, I've read just about every thread that comes through. In short, the consensus is SWGs won't cause any more damage than the pool water itself. Cheap materials and improper chemical balance cause damage to pools, not the nominal level of salt required for a SWG. Other forms of chlorine and pool chemicals leave salt behind as a byproduct. It's not unusual to see non-SWG pools with saline levels in the 2,000+ ppm range. Most SWGs require a min salt level of +/- 3,000 ppm. Ocean salt levels are 35,000 ppm. Having dealt with both SWG and non-SWGs in my years of pool ownership, I would have no problems recommending one.

If I was building a new pool, there's no way I would allow a once-per-week service to take care of my pool. Pools need almost daily maintenance and chemical adjustments to prevent damage and to ensure a safe swim environment.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
5,982
Southern OK
Welcome to TFP :) Great question (y)

Bottom line is a chlorine pool is a salt water pool especially where you live... In 1 to 2 years of dumping liquid chlorine, muriatic acid in your pool you will have the same amount of salt in it as if you have a salt water pool... That is exactly why we tell people to get a salt test kit and find out how much salt you already have in the pool... If you test your pool I bet you are over 2000 ppm salt right now, Salt water pool territory..

Now that we have established you already have a salt water pool has your equipment lasted 50% of the time? I guess no....

You may see a PH rise if you switch from pucks because pucks are acidic so you are adding acid each time you put another puck in...

My SWG has lasted 7 years no issues at all, with another cell it will last another 7 years at least... SWG are easy, I can leave for a month and know it will still be working when I return... Once it is balanced it just works.. I do test my pool at least 2 times a week when I am here...

All chlorine costs just about the same (right now it has been more expensive for liquid if you can find it) You just pay up front for a SWG..

What they are really saying is they want you to use a service and pay them monthly when you can pay yourself to take care of your pool very easily :)
 
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rstrouse

Well-known member
Jun 17, 2020
83
California
The reason why it is different is that under most circumstances the chlorine level will not be low. When you go away for a couple of weeks or don't have enough daylight for testing you can have some assurance that sanitizer levels are good. I get it that some folks get to test their water every day but some of us are not that fortunate. With the cleaner in the pool running its daily route and the chlorinator doing its job, I can be pretty sure that it will need acid when I test it every couple of weeks if I am busy, but the pool will look good. If not for the chlorinator, I can be assured that the chlorine level will be low as indicated by the green tinge on the plaster.
 

mguzzy

Gold Supporter
Whoa, Penn'.. that is quite a first time post.. and welcome to the community! My colleagues above have hit the high points. Lets take your concerns one at a time.

Hi. Longtime lurker and user of the TFP method on my 45-year old, directly chlorinated pool.
Then you probably already know there is a huge acceptance of SWG's on this site. And a SWG pool is the same as a Dosed pool. The only difference is the method of adding chlorine.

I bought the house 3.5 years ago and I'm looking to resurface, replumb, and update the hardware.
Sounds like the perfect time to add new tech like an SWG. I have lived with 4 pools throughout my life. The last one came with the house I currently live in. And I added an SWG when I upgraded everything on the equipment pad back in 2005.. that was the best decision I ever made.

I am planning to use a pool service, at least to start, but I might pick it back up down the road.
Why? If you switch to a SWG, there is even less of a need for a pool guy. You already know how to do the TFP dance, its the same with an SWG, except you don't have to haul jugs. Unless you just like paying someone to scoop leaves out of your pool once a week.

The builder I like the best and who seemed to be the most knowledgeable (he was the owner of a 25-year pool builder) said he'll do a SWG if I twisted his arm, but he'd rather not.
There are huge changes in the pool industry with respect to pool maintenance and servicing. I find the old school pool guys don't keep up on this. Ask most pool guys about the CYA to CL relationship and you will most likely get a stare.

He said he used to do them extensively in 2005-2012, but that many of those systems either rotted out due to metal fatigue from poor maintenance or the owners chose to switch to directly chlorinated due to various reasons.
Well there ya go! its not an issue with the SWG, its how you care for you pool. If an owner doesn't bother to take the time to figure out how to care for their pool, they are going to have issues either way. Somehow SWG's got blamed for it. Probably because as others said, those owners thought an SWG was a set and forget technology. No it isn't, there are a few things you have to do, but its a lot more less hands on that daily dosing.

He said if they work on a neighbor's pool, they might squeeze us in, but otherwise we'd have to go with someone who doesn't do a great job at adequately maintaining the pH levels with muriatic acid and that will lead to corrosion.
You are already doing that if you are doing the TFP method

He also gave me some other reasons that seem to pan out by Googling: SWG pools
Surely you don't believe half of what is on Google... and Morgan Fairchild is my wife too!

start with an already high dissolved solids number that make balancing difficult, chronically high pH, instead of dumping liquid chlorine I may be dumping the same amount of muriatic acid weekly, pool decking may not last as long, SWGs rarely last more than 3 years, and pool equipment will last 30-50% less time. His only gripe about directly-chlorinated was high CYA levels from pucks.
Well he got one thing correct... Pucks add CYA. Yes, SWG cause your pH to go up. Its a part of the physical process. So I add maybe a 1/2 cup of MA/week. That is far less than the amount of Cl would I would be adding if I was manually dosing. Salt adds to the TDS.. so Duh, they are going to be high. but that is not what you should be looking at anyway. Pool decking longevity is usually a function of something else besides the salt for an SWG. The salinity is just too low to affect any decking I can think of. If someone's decking was degraded, then it was from bad pool management anyway. And how long a SWG lasts depends on how you care for it.. if you do a lot of acid washing it reduces the life of the SWG.. but then again if you doing a lot of acid washing to remove scale, then you need to look at your pools chemistry. See below on how long my cells have lasted.

I asked about the salt water feel on your skin and he said from his experience only some people with sensitive skin will notice it, but that's really more about a well-cared for pool than salt vs. direct chlorine.
Not true.. everyone can feel the difference in a salt pool. The additional salt in the water changes the specific gravity.. so there is a physical difference. Its closer to the same chemistry of your body, so you don't prune up (as fast) and you float higher. The effect on people with sensitive skin is that the CC's are broken down by the SWG process as well.. but if you are properly maintaining your pool, you are watching out for the CC's anyway.

Here are some facts I've gathered about my area: We apparently have some of the hardest water in the country at ~245ppm on average.
You might want to consider adding a water softener for your fill water.

Pools are year-round here, but the water temp in January can reach 55F even with a spa used occasionally.
I don't close mine at all... but no one wants to swim in it when its in the 50's. But it doesn't freeze. SWG controllers will reduce the Cl output in the winter when the water temp is lower, and shut off when its in the 40's (Mine SWG does per its specs). So there is a span of about 3 mos (Dec, Jan, Feb) where I have to manually dose. But its hardly anything. I barely went through 3 gallons this winter. The bio activity is lower in cold water, the sun is lower on the horizon so its not degrading the FC as well. So .. my answer to this is So what.

Around 2010, pools in my area were being built 90% SWG and 10% direct chlorine. Now, per all of the builders it's about 60% SWG and 40% direct chlorine. Water is very expensive here, as is electricity. Partial dumps and refills are highly frowned upon during droughts, which are pretty much always here. Few trees, high sun.
They hardly use any electricity. I would expect there were a higher percentage of SWG put in around the 2010's.. they were new and everyone wanted one. The technology has only gotten better. I put mine in around 2005, and have been using the same controller. I replaced the first cell after 9 years, and I am 6 years on the second one so far. You shouldn't need to drain your pool. I haven't. SWG's like trees. Mine does. The shade from the trees means less FC loss due to UV degradation. And that makes the SWG not have to work so hard.

Sorry for going on so long, but after searching this site and most of the Internet it seems like people are in 1 of 2 camps: pro-SWG and it's a personal preference. No one really seems to be "always direct chlorination," but some are "never SWG." This makes it really hard to make a decision since it seems like everyone has their own opinions, but facts are hard to come by. I'm really more concerned about the water quality on skin and the longevity of the pool and equipment. I figure the maintenance costs will even out otherwise.
Ask every question you have.. that is what we are here for! Everyone on this site is pro-SWG.. its more "can I afford it". On this site at least I am seeing more owners switching to SWG's due to the Covid, citing Chlorine availability or from sitting at home staring at their pool and looking for something to do. On the rest of the internet you get the whole range of kooks, many that don't know what they are talking about.

Has anyone here every had both or converted from one to the other so they can offer some direct experience between the water feel between the 2 and the maintenance?
Yes, that would be me!
 
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Newdude

Gold Supporter
TFP Guide
Jun 16, 2019
6,925
NY
Hey Penns and welcome !! So if you can find any legit beef with a SWG it’s either:

1) equipment failure (which happens to any products of any kind)

2) a pool owner didn’t do it right and failed miserably. Either by not maintaining the proper chemistry or by using cheap materials in and around the pool that either pool would have ruined.

We have one member (Fred) who has a hard time with scaling even though he is extra vigilant with his chemistry. It’s a freakish anomaly that has to do with his specific pool and we may never get the answers as to why. But even he says it’s worth it overall. Darn near everybody else swears by it / take it out of my cold dead hands style. It’s even hitting the above grounders where the SWG costs can be 25-50% of the pools cost.

There are still plenty of people, both in the industry and members here that are set in their ways and still swear by liquid dosing. Nobody is wrong, both ways work, and have pros/cons.

But the overwhelming majority of the SWG ‘cons’ involve the upfront cost. After that it’s a grand slam.
 
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poolnoobgrandma

Gold Supporter
Sep 15, 2018
582
Seminole, FL
We will celebrate our 2 year pool anniversary in June. Hubby was fine with getting a pool, but I would be in charge of maintenance. We did 5 things that make it a breeze:
1) Screen enclosure. We get lots of pollen at various times of the year, but no leaves
2) Robot cleaner. We throw Gilligan in, and I hose off the filters once in a while.
3) SWG. Keeps the chlorine levels where they need to be, as long as it's set right and I'm staying aware of pool conditions.
4) Get the pool math app. Track tests and determine amount of chemicals to add when needed.
5) Join TFP. When something "new" comes up, a quick search usually points me to the solution. If not, the helpful folks here respond very quickly to any questions (as you have discovered).

I'm 60, hubby is 67, and we plan to age in place. So someday we'll get help with the pool. Maybe monthly have someone come and clean the filter, check the salt cell, add salt if needed (that's the literal heavy lifting).
I could get a pool service if I wanted (that would qualify as taking care of it.) I prefer to know exactly how my pool is every time I get in. The SWG makes DIY pretty darned easy.
Note: here on the west coast of Florida, ALL the builders recommended SWG.
Best of luck, and Welcome!
 

red-beard

Gold Supporter
May 27, 2019
955
Houston, TX
Pool Size
25000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite Pro (T-15)
I want to add one more thing on the reason "salt cells don't last". Here it is recommended to get a Salt Cell this is 50-100% oversized, so you run it less. The cells have a "finite" life. I run mine 24/7, but at a reduced level (10% in the winter, 20-25% summer). If I take care of it, I should get about 7 years of life from the SWG. I pull the cell every time I clean filters (3-4 times a year), clean the plates and acid wash if needed.

But the big thing about the SWG is that it works all the time. I can go on vacation and not worry my neighbor will forget to add chlorine.

With my pool robot, and the SWG, I only need to test about once per week. I can test, brush my walls and spa where the robots doesn't go, etc. and be done in less than 1/2 hour. Once a week. I can enjoy my clean perfect pool instead of fighting algae because my CYA is out of whack from tablets.

I drained my pool in April and converted to SWG the first week of September. My pool in 4 months was nearly 2000 ppm salt. I had a Salt Water Pool.
 
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cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
5,982
Southern OK
I want to add one more thing on the reason "salt cells don't last". Here it is recommended to get a Salt Cell this is 50-100% oversized, so you run it less. The cells have a "finite" life. I run mine 24/7, but at a reduced level (10% in the winter, 20-25% summer). If I take care of it, I should get about 7 years of life from the SWG. I pull the cell every time I clean filters (3-4 times a year), clean the plates and acid wash if needed.

But the big thing about the SWG is that it works all the time. I can go on vacation and not worry my neighbor will forget to add chlorine.

With my pool robot, and the SWG, I only need to test about once per week. I can test, brush my walls and spa where the robots doesn't go, etc. and be done in less than 1/2 hour. Once a week. I can enjoy my clean perfect pool instead of fighting algae because my CYA is out of whack from tablets.

I drained my pool in April and converted to SWG the first week of September. My pool in 4 months was nearly 2000 ppm salt. I had a Salt Water Pool.

I never acid wash mine, it will last longer the less you acid wash them.. :)
 
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Vickery

Gold Supporter
Silver Supporter
Feb 22, 2009
445
Perfection, NC
I switched to salt in my first pool (agv) in 2006 (or there about.) Moved to a new pool in 2018 and brought the swg with me. I bought a robot last year. Except for snagging leaves, crayfish, frogs and other critters (which happens regardless of the chlorination method) I spend about 10 minutes a week on pool maintenance. Crystal clear, sparkling water. Yeah, pools are just SOOO much work!
 

Grogu72

New member
May 3, 2021
2
Tucson
So I'm on the verge of making this leap of faith as well. Could still go back to getting the chlorine levels correct myself but it does seem like more work than it should be as I keep reading the comments here. Pool is drained and will be cleaned soon. Minor chipping issues will be fixed as well. If there are any other recommendations to do before converting would like to know about that but I suspect will be in a different thread as I keep exploring this wonderful site.

One other thing besides the reduced maintenance that that may have swayed us to SWG is we keep hearing about a chlorine shortage coming. Is that true? Having a SWG certainly can minimize that that risk if that becomes a reality.
 

mguzzy

Gold Supporter
Could still go back to getting the chlorine levels correct myself but it does seem like more work than it should be as I keep reading the comments here.
Go for it. You won't be disappointed. You will still need get your Cl levels correct yourself, and then hand it off to the SWG to maintain it.

Is that true? Having a SWG certainly can minimize that that risk if that becomes a reality.
Yeah, its a reality, there was a major puck manufacturer that went off line. But not so much for Liquid Chlorine.. AND it depends on where you live in the country since the products are produced regionally.
 
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poolnoobgrandma

Gold Supporter
Sep 15, 2018
582
Seminole, FL
So I'm on the verge of making this leap of faith as well. Could still go back to getting the chlorine levels correct myself but it does seem like more work than it should be as I keep reading the comments here. Pool is drained and will be cleaned soon. Minor chipping issues will be fixed as well. If there are any other recommendations to do before converting would like to know about that but I suspect will be in a different thread as I keep exploring this wonderful site.

One other thing besides the reduced maintenance that that may have swayed us to SWG is we keep hearing about a chlorine shortage coming. Is that true? Having a SWG certainly can minimize that that risk if that becomes a reality.
I'm overdue on testing my pool, but it's so sparkly that I know nothing bad is happening. Thank you SWG!! (gonna test after my current meeting is done)
Update: Just tested. Chlorine was perfect (5). pH was a little high, so in went some MA.
20 minutes and I'm jumping in.
 
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poolnoobgrandma

Gold Supporter
Sep 15, 2018
582
Seminole, FL
I switched to salt in my first pool (agv) in 2006 (or there about.) Moved to a new pool in 2018 and brought the swg with me. I bought a robot last year. Except for snagging leaves, crayfish, frogs and other critters (which happens regardless of the chlorination method) I spend about 10 minutes a week on pool maintenance. Crystal clear, sparkling water. Yeah, pools are just SOOO much work!
We added a screen enclosure to the SWG and robot for ease of maintenance, so no critters or leaves.... it really is a pretty danged Trouble Free Pool!
 

WilliamBaggins

New member
Jan 17, 2015
3
batesville,ar
I switched from sw to chlorine. I got sw because it was sold as no maintenance. Pool is 50000 gallon plaster . pH was a major problem for me. Chronic pH of 8.5 to 9. A gallon of acid a day. I finally ignored the high pH and developed a coral reef which I recently polished down. pH still trends high, a gallon a week. Would try salt water and test yourself with a colorimeter. If you start getting difficult to manage chemistries, convert to chlorine. You would be out the cost of the sw generator, and a refill.
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
5,982
Southern OK
I switched from sw to chlorine. I got sw because it was sold as no maintenance. Pool is 50000 gallon plaster . pH was a major problem for me. Chronic pH of 8.5 to 9. A gallon of acid a day. I finally ignored the high pH and developed a coral reef which I recently polished down. pH still trends high, a gallon a week. Would try salt water and test yourself with a colorimeter. If you start getting difficult to manage chemistries, convert to chlorine. You would be out the cost of the sw generator, and a refill.
sounds like your TA was high.. what is your TA and what test kit are you using? Once you drop your TA to the recommended levels your PH rise will be minimal :)
 

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