The PROs and CONs of SWG

Flakes are often a sign of a water chemistry imbalance. If you keep your CSI negative, flakes are much less likely to form. Adding 50ppm borates will also help keep calcium from scaling in the cell. I have 850ppm CH and my cell has NEVER needed to be acid cleaned.

I have borates as stated above but not high CH but I too have never had to acid clean or even clean my cell.
 
My wife and I are thinking about going with a SWG moving forward. I consider myself now very astute with the TFP methodology but I to be honest, I'm not thrilled with having to dump bleach every 2 days to keep my FC level nominal (we are full sun and typically keep my CYA lower (30-40)).

I was hoping I could get some stories from folks out there who DID go SWG and are TFP'ers and what they think of the experience and the adjustment with respect to maintenance (in fact, I just read chem geek's guide which will probably be my reference going forward).

Any feedback would be much appreciated.

I switched from tabs to SWG ..
Love it !!!
I was wasting so much money on stuff at the pool store , my cya was always over 100 and i fought the algee battle all the time. Until pool school and a lot of nice folks on this site helped me.
Now I follow the recommended levels and i have a trouble free pool .
SWG is really the way to go. Slight learning curve but if you have a TF-100 and know how to use it , you will love it.. I bought a SWG for a 60k gallon pool ( my pool is only 30k ) better to oversize and turn it down if you need too .. Good luck !!!
 
Flakes are often a sign of a water chemistry imbalance. If you keep your CSI negative, flakes are much less likely to form. Adding 50ppm borates will also help keep calcium from scaling in the cell. I have 850ppm CH and my cell has NEVER needed to be acid cleaned.

My csi is always negative, I never have added borates though. going from memory here are my last results; fc 5, cc0, tc5, ph7.4, ch 390, ta 90, salt 3200, cya 50, temp 78, this yeilds a csi of -.25. Thats interesting about your ch, maybee the borates are the key? I've had the flakes the whole time I've had the pool and have cleaned the cell 4 times.
 
I had vinyl with pucks and now in-ground plaster with SWC.

Some people like the physical feeling of saltwater (some say silky) and the extra buoyancy. Sounds like you've already read that you don't need a SWG to get this. You can just add salt to your pool for the nice feeling and higher buoyancy. For me, that would be a $100 reversible decision vs. $1200 with the SWG.

My SWG spec is 4,000 ppm with 3,000 minimum, and the pool builder said you won't even be able to taste the salt. That might be true at 3,000 ppm for different chlorinators, and I think this does vary by person, but I can definitely taste it, albeit not objectionable in any way. The upside is that many people find the higher salt easier on the eyes.

We have an SWG and like it, and for what it's worth here's my decision-making experience including a bit of advice I got from a poolie I play golf with, along with advice from most everyone I know. We have incredibly high residential pool ownership here, so most adult Australians know what an SWG is and have an opinion on it!

We don't have any water features with natural stone, so that's no issue for us. Another family member has a natural stone water feature that they leave turned off because of 1) noise, 2) evaporation and 3) salt deposits on the stone that have to be hosed and rubbed off. Salt corrosion of stone paving doesn't come up here, and if you ask, people look at you like you're from outer space. That said, people have stopped using the local sandstone as much, and prefer harder imported stuff. Lots of salt pools have limestone and travertine. I agree this is very regional - e.g. we don't have to think about freeze-thaw - but could you rinse everything down before winter, salt or not? Anti-salt people talk about the stone wearing out prematurely, but they're talking fewer decades. I think we'll be sick of our beautiful limestone paving and putting down iPhone paving or some such by then, haha. At any rate, a liquid chlorine pool also has salt in it, so this entire issue seems like a red herring to me, along with general corrosion of metal near the pool.

With respect to convenience, without the SWG I'd be lugging ~660 lbs (300 kg) per year of 12.5% pool chlorine, one way or another. We still keep a jug of chlorine on hand and dump a bit in before any kids parties (KimKats advice) along with a cup or two after.

My wife loves saltwater, and it's the normal market-dominant way to do chlorination here in Aus, so we have an SWG (pool builder throws it in, and no credit if we left it out - I think PBs buy them pretty cheap.) Without it, I would have found or figured out an adjustable metered liquid chlorinator.

My friend's view is that SWG's are solid, though he's not a fan of all brands, so DYOR. He did say that any controller can get fried by things like lightning and bugs nesting inside, and the $400 replaceable part (the cell) can burn out prematurely from poor choice of brand, or failure to clean the cell when needed. All models we looked at have reverse-polarity cleaning, so the cleaning of the cell is less frequent than it once was. Mine has not a skerrick of calcium on it after five months.

On my own, I would have stuck with fresh water, but my reason is just plain weird! I love letting all the air out of my lungs and seeing how long I can sit on the bottom! Can't do that in saltwater, cause I just float up no matter how much I empty my lungs in any saltwater pool I've been in. Maybe if I get skinnier? :)

Upward pH creep is previously mentioned and I'm currently adding a bit under a quart (litre) per week or 110 lbs (50 kg) per year, but as I learn from the experts here, my trend is down. If I had listened to the pool store, it would be at least double that because of their much higher recommended total alkalinity. I'm far from qualified to comment on this topic. I'm just a new-to-salt person who is starting to get it. I'm hoping I can get my acid down to a couple of cups (500 ml) a week. I've learned here that this will vary by pool, but if you're using acid now, expect it to go up a bit.

The saltier water can damage lawn and garden, so I put in perimeter drains as an extra line of defense in addition to the overflow line (we get some heavy rain here at times). That's probably overkill, but I feel good about it :).

Most comments here say cost is a toss-up, which I think helps the decision be based on other more interesting factors. My numbers show it as cheaper by a fair bit, after considering initial purchase, cell replacement, electricity and increased acid use. That said, I think cost favours SWG only if the initial purchase and cell replacement cost is divided through 5 years (e.g. you're not planning to move house).

Summary for me is that if I build, buy, borrow, win, or take over any other pool... it will be SWG!
 
If we didn't have an SWCG, I would get one. That being said, it's a huge advantage to know what to do when the system fails and what signs to look for. You already know how to deal with this, since you are currently adding bleach manually.

In other words - an SWCG is very convenient. It is also likely to periodically fail, and you should be prepared to detect and handle that when it happens.
 
FYI, I have a St Augustine lawn in Texas, and even when backflushing into the yard, I have never had any issues with it harming the lawn. I would not let plant damage scare you out of salt water.
 
I take care of lots of pools, all different types.

Find out what's in your water so you can take precautions. High in CH you'll need to be diligent to prevent scale on the blades. High ALK and you'll be lowering the PH often.

If there is an auto cover, you must be diligent in testing the chlorine levels... particularly with vinyl.

As for effects on liners, SWG, chlorine, tabs, etc. low PH is almost always the culprit of damage to liners. However, I have seen extreme fading in SWG pools where there are auto covers. People think they can leave it an never check the FC level and it can get extremely high and fade the liner. I've seen more fading in auto cover liner pools than in manually/tab feeder chlorine pools.
 
However, I have seen extreme fading in SWG pools where there are auto covers. People think they can leave it an never check the FC level and it can get extremely high and fade the liner. I've seen more fading in auto cover liner pools than in manually/tab feeder chlorine pools.

As you indicate, it's a failure of proper pool maintenance by the pool owner, not a problem with the SWG.

A tab feeder running continuously on a covered pool would not fade the liner because it is delivering both chlorine and CYA to the pool water. This has the effect of decreasing the active chlorine concentration (hypochlorous acid) over time. Hypochlorous acid is what bleaches liner colorants (particularly the blue dyes used in vinyl). By contrast, an SWG simply adds chlorine to the water with no increase in CYA therefore the active chlorine level would increase with time and buildup. The cover eliminates UV exposure which is the primary source of FC loss.

As long as regular pool water testing is performed and a covered pool is opened up a few hours each week, then the risk of liner fading should be minimal.
 
As you indicate, it's a failure of proper pool maintenance by the pool owner, not a problem with the SWG.

A tab feeder running continuously on a covered pool would not fade the liner because it is delivering both chlorine and CYA to the pool water. This has the effect of decreasing the active chlorine concentration (hypochlorous acid) over time. Hypochlorous acid is what bleaches liner colorants (particularly the blue dyes used in vinyl). By contrast, an SWG simply adds chlorine to the water with no increase in CYA therefore the active chlorine level would increase with time and buildup. The cover eliminates UV exposure which is the primary source of FC loss.

As long as regular pool water testing is performed and a covered pool is opened up a few hours each week, then the risk of liner fading should be minimal.

Yes, exactly. I had a client stop service at the end of September because no one was using it. He never turned it off... He called my associate (I don't do inground closings) and by the time the pool was closed, in mid November, the liner had faded significantly!
 
I am in the exact opposite position as you. I have had a Jandy 1400 SWCG since day one. It has been a breeze to own a pool with SWCG. Just test a few times a week and add MA to lower Ph a couple of times a week and keep an eye on all of your levels, especially CYA. A few days ago my Jandy system started throwing a 170 error code. I found a troubleshooting flowchart on this forum and followed it. Turns out it is a bad sensor. New one ordered but hauling bleach and dosing it everyday is a pain the arse. I am going on vacation in two days so I had to hire my neighbors son to dose it with bleach while I am gone. There is no way I would ever own a pool that is not auto chlorinated with a SWCG. The time and money saved is worth every cent in my opinion.
 

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I really appreciate all the feedback.

Yeah, I'm pretty much fine with TF-100 and TFP methodology. It seems PH creep seems to be an issue for some.

Is there any issue with adding a heat pump in the equation to all of this?
 
This won't make any difference. If you had one running at 100% to meet your needs vs a larger one at 10%, you are still putting out the same amount of chlorine.

Actually, it does make a difference. pH rise from the use of an SWG is not a result of the chemical reaction that forms chlorine. The rise in pH is caused by aeration from hydrogen gas formation at the electrodes. It's exactly like running a waterfall or a bubbler - CO2 gas is displaced from solution and the bicarbonate alkalinity consumes a proton to resist the change in equilibrium. It's that consumption of a proton that causes the rise in pH.

So, having a larger cell means running it a lot less to produce the same amount of chlorine as a smaller cell. This in turn leads to less aeration and less pH rise.

Depending on where you keep your alkalinity and the pH/TA of the fill water you use (as well as if borates are present), then the pH rise will be different for different pools.
 
I admit, it's been decades since my chemistry days, but logic tells me that a given energy input will result in the same H2 output regardless of the size of the cell. The way I understand it, the cells differ in the amount of energy they potentially can put across the water to generate chlorine. So if I run a small cell at 2v, or a large cell at 2v to give me the same chlorine output, the total energy and H2 output will be the same. The only difference is that on a larger cell I could potentially turn it up higher and output more chlorine, and more H2. Kind of like in a 30 mile per hour zone, a Corvette and a Prius are both going 30 mph, but one has more unused potential.

I'm not arguing, I'm trying to understand how this isn't the case. If you are right, I'm going to be much happier now because my pH was swinging like crazy before, even with 50 ppm borates and TA of 70.
 
Actually, it does make a difference.

Wrong.

Cl2 production is directly proportional to the total number of electrons (i.e. electrical current) that moves through the circuit. A "bigger" SWG simply has more electrode surface area (e.g. more plates) than a smaller one does. Consequently, the larger SWG can generate more chlorine gas per unit time, simply because the larger surface area anodes enable more chloride ions to get oxidized (i.e. they can "consume" more electrons per unit time).

Larger SWG units can produce the required chlorine amounts in shorter time than smaller units, but the amount of electrons required is the same in either case.

Stoichiometrically, SWG electrolysis generates one H2 molecule for every molecule of Cl2 that is produced. So the amount of H2 produced (i.e. the driving force of pH rise) only depends on how much chlorine is generated...not how big the SWG is.
 
So, having a larger cell means running it a lot less to produce the same amount of chlorine as a smaller cell. This in turn leads to less aeration and less pH rise.
Does it? I would think that the same amount of FC added to the pool (big vs small cell), would generate the same amount of hydrogen bubbles given the required reaction balance. A larger cell has more area to generate not only more chlorine but also more hydrogen per minute. It should be directly proportional to production rate which in turn is directly proportional to the cell area. So I don't think it should make a difference.
 

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