Effect Of Saline System On Plaster

[williams15470]

I just got off the phone with my pool service, asking them about converting my pool to a Saline system. I've heard so many wonderful things about the Saline pools that I thought now might be a good time to convert. Imagine my surprise, when the pool tech did NOT recommend the Saline system!! He said "studies" are now coming out showing that pools with plaster-coated surfaces, are now showing significant damage caused by the Saline water treatments. Has anyone else heard about this, or, worse yet, encountered any such problems?? Everything I've read, only mentions the pros and cons of Saline vs. Chemicals. I haven't heard ANYthing about the salt damaging the plaster coating of a pool. Any input would be GREATLY appreciated!!

By the way, our pool will probably be due for a re-plaster in the next couple of years, but I was told re-surfacing with Pebble-Tech would probably DOUBLE the cost!! Is this true?? I have a very large pool and, needless to say, can't afford a "double" in cost to re-surface it!!!

[Strannik]

You are not supposed to put salt in a pool with fresh plaster for the first month or two. Other than that - there is no problem with using salt water systems in plaster pools. Damage to the plaster is caused by improper water balance, not by salt.

[muss51]

I have not heard this at all and I have not encountered any plaster surface problems in any of the pool I work on. Usually the only chemistry problems these have are that they increase the pH because of the CO2 bubbles that are released which aerates the water.

[williams15470]

So, would you think my pool service is not recommending the Saline system because...

a) The Saline system is easier to maintain and practically self-servicing

Meaning I probably won't need the pool service anymore to treat my pool with chemicals

c) Meaning they won't be making over $2,000 a year from me anymore

Hmmmm........ what would be your guess??

Is the Saline system REALLY as good as everyone says it is? Who is the best person to install such a system? Should I trust my pool service company to install the system (even though they don't "recommend" doing so...) or are there Saline system "specialists"? How do I find one in my area (San Antonio, TX)??

Again, any help or recommendations would be GREATLY appreciated!!!

[Strannik]

It's easy in a sense that you don't have to add chlorine. You still have to maintain proper water balance though. Installation is easy, depending on a system. Some systems are virtually plug and play, others require an electrician to install them.

[williams15470]

I think I'm going to proceed with having my pool changed over to the Saline System.

Do you have any recommendations of which system (brands) are the best? I'd like one that is, not only simple to maintain, but dependable as well. I don't intend to install the system myself (I want to make sure it's done right!!), but I would like to maintain it after it's stabilized. Is this possible?

[Strannik]

Well my advice would be AutoChlor, but it's biased, and it's going to be hard to find in US. I think saltcells.com sell them, but not sure.

It's a very reliable and really simple to use system. Installation is plug and play, system is very compact and light due to use of switch mode instead of transformer.

You can look up more if you follow the link in my signature.

If you want more features like salt readings etc, you should probably go for AutoPilot Digital, or even AutoPilot Total Control (or whatever it's called). General feedback about them is pretty good.

With regards to maintenance, do you want to maintain the system yourself, or maintain the pool yourself?

System maintenance is very easy, you set it to required chlorine level and then you only need to check and add salt as necessary, and probably clean electrodes once in a while, depending on your water hardness.

Now water balance is a bit trickier, but a lot of people do it themselves too. There is a decent guide somewhere on the net, i think written by chem geek (or was it waterbear?). You would need to also buy yourself a test kit, and learn how to do tests. A lot of people find it very exciting and there is certainly nothing impossible about doing it yourself.

[PaP dude]

I don't know if you already made a purchase on an electrolytic cell for your pool, but a company called "Resilience" has put an excellent salt chlorinator out on the market. They have added a unique feature to there model. The plates (anodes and cathodes) vibrate as the solution of chloride ions and sodium ions pass over them. This reduces the scale build up on the plates caused from calcium/magnesium...etc. found in your water. They have a few other cool things about their product that you should look into.

[chem geek]

williams15470,

Since you are in Texas, your pool tech may be influenced by this blog in terms of downsides to salt pools. There may be a bit of group think mentality going on, but even if some pools had stone deterioration or metal corrosion, that's not the same thing as plaster and I have seen zero reports of increased plaster corrosion from salt pools. Technically speaking, a salt pool at 3200 ppm TDS (for 3000 ppm salt level) does have a lower saturation index by about 0.2 so that is a little more corrosive to plaster, but easily mitigated by keeping the pH a little higher and/or having a higher Calcium Hardness (CH) level. It's not a big deal unless the pool chemistry was "on the edge" already. Even the incorrect "modified for the pool industry" Langelier Saturation Index (LSI) accounts for TDS though it does not do so as much as it should.

The easiest thing to do is to have your pool tech prove to you what he is saying by showing actual problem pools and correlating that to salt vs. non-salt as well as looking at other factors such as improperly maintained water chemistry. He should also refer you to the specific studies and if you post those (or PM to me) then I can look at them and give you my opinion about them. Most SWG pools say to use 60-80 ppm CYA so maybe he's thinking about this study that showed plaster degradation at high CYA levels. However, I've since found out that this study was flawed and in any event the CYA level in SWG pools is much lower than that in the study.

There does seem to be something going on in Texas and Arizona more than in other parts of the country, but as to whether this is related to weather, local stone materials, differing local codes or enforcement (say, for bonding) or something else is unknown. That doesn't mean that the higher salt isn't a factor, but rather that it may be the salt plus other factors combined that make the problem show up or get reported more in some areas.

There is no question that higher TDS means higher conductivity of the water which makes galvanic corrosion go faster, but this doesn't mean that "faster" actually matters because such corrosion could be already very very slow. It can also be almost trivially mitigated through use of a zinc block (sacrificial anode) electrically connected to the bonding wire (magnesium block if there is aluminum used, as with electric safety covers) and buried in moist soil. As for stone degradation, this is very much a function of the stone itself where soft (water absorbing) stones are most susceptible such as soft limestone. Again, mitigation is either using less absorbent stone (or a "fired" stone) or sealing the stone regularly. Same is true for cement -- we seal our "flagstone simulated" cement every year and we don't even have a salt pool.

Most people that have a saltwater chlorine generator (SWG) system love them and have little or no problems with them. The main issue is that such pools tend to rise in pH due to the hydrogen gas bubbles produced in the SWG that aerate the water driving carbon dioxide out. This can be mitigated through having a lower Total Alkalinity (TA) level and by using Borates (typically at 30-50 ppm) both as an additional pH buffer and algaecide. This, combined with the higher CYA levels, lets one reduce the SWG output thus reducing the outgassing. By the way, the recommended range of 1-3 ppm FC for SWG pools is not correct and you should maintain an FC level that is at least 4.5% of the CYA level to prevent algae (this FC level is lower than the normal 7.5% level for manually dosed pools because there is some superchlorination of the water passing through the SWG cell that helps kill free-floating green algae and the dosing is more consistent).

Richard

[AlphaChaotic]

It sounds as if you've found yourself a good pool store. Most pool sales professionals work on commission so for a salesman to take the higher road, and lay out the true pros and cons as he now knows them, so as to allow you to make an informed decision, isn't as commonplace as it should be. First off, I suppose I should lay one blatant falsehood surrounding salt systems and "salt generators" and the like: A salt system is not a true alternative to a chlorine sanitizing regimen! That theory rests on the foundation that salt, somehow, by its own nature is some kind of sanitizing agent. It, in fact, is not. It is true, however, that it is significantly different from the "traditional" chlorine-based regimen. The whole concept of salt water pools centers around electrolysis. Most salt systems are made up of two components: A cell (where all the magic happens) and the control panel (in most instances waterproof). The control panel provides information to the user/owner concerning your current salt content measured in ppm (parts per million), and the options to super-chlorinate and and internal timer allowing you to set the pump and filtration system to operate at two separate intervals in a 24 hour period. Some people, indeed run their pump 24 hours a day; it's just that I find two separate 6 hours periods in one 24 hour period to be just as effective and much less aggressive on the power bill. The cell will resemble a battery. Inside are usually 4 to 5 titanium disks. Now it needs to be understood that this cell installs between the pump and the filter. As water is returned to your pool, it passes through these titanium disks which are receiving a small electrical charge (depending on model, anywhere from 1-4 amps.)

The salt, which has already been added to the pool, in the meantime has been doing a little prep-work of its own. Once salt enters the water, it breaks down; one of those splits being an inactive chloride ion. That ion, mixed with the water, passed through the charged titanium plates, becomes active as well and then become an active chlorine ion. See: Chlorine Pool.

Another falsehood I hear repeated often enough is that employing a salt system and owning a salt water pool is markedly easier to maintain in comparison to chlorine. About the only thing I've found it to be easier on is the pocketbook. What these systems do for you is eliminate the need to utilize chlorine pucks and shock your pool weekly as part of a scheduled maintenance as set up by your local pool store. Its also not true that you never need to shock your pool when running a salt system. If algae gains a foothold in your pool and when even running your salt system at full capacity, you find yourself not being able to maintain a chlorine reading, it would at that point be necessary to shock your pool with a non-chlorinated shock, which tends to run a little higher than standard granulated chlorine. As well, you still to need to monitor and maintain proper alkalinity, pH, hardness and stabilizer levels. Doing so requires manually adding chemicals and re-treating if necessary. And thats why I say its not so much easier to maintain, just less costly to maintain. I find, on average, whereas you may spend 90 bucks a month on chemicals used to properly maintain a chlorine-based regimen, you'll find yourself on average, spending 20-25 dollars a month. Most systems can or nearly can pay for themselves in three years.

And then you get to the main disadvantage of a salt water pool and the original inquiry: The corrosion to your metal pool components caused by the electrolysis process that's tantamount to the system. It's going to happen! Let me repeat that: It's going to happen! Whether you have an above-ground pool or in; whether it be to metal pool components or to your brick coping or your concrete deck or your flagstone hardscape.... Yeah, you get the idea... Not what you've been hearing right? Well the truth of the matter is this: Your most widely used means of negating the corrosive nature of the charged salt content in the pool is the placement of a zinc disk or an anti-electrolysis weight, placed into or bolted in to your skimmer basket. These seem to be about 25% effective at protecting the metal components of your pool that sit below the water line. You can also ask your salesman about installing an in-line zinc anode. These, when properly installed and bonded into the system grid are 95%-100% effective at protecting metal components below the water line of your pool. In a nutshell, and according to the principles of galvanic corrosion, when two metals come into proximity to one another in an environment made active by the electrolysis process within the system, the corrosion will be drawn to the weaker of the two metals. Titanium, on the galvanic spectrum (remember titanium is used the cell of your salt chlorine generation system), is one of the strongest metals. So at that point most of the metal components of your pool (skimmer screws, light niches, ladder railings, etc.) would fall victim to the corrosion process. But by placing the zinc anode into the mix, you, in essence sacrifice that metal to the greater good of the pool. An added bonus: As it releases itself into the pool, it tends to coat the metal components present in the pool with itself to provide an even greater level of protection. So when properly changed, on average once every 6 months, you save yourself that hassle and get to focus on enjoying the pool itself and remembering the reason you signed up for all this anyway =)

At this point you'd probably be ready to sign on the dotted line. Right? But did you notice I mentioned several times before that those processes only protect the metals lying below the water level? Thats right: Your top rails will still fall victim to the corrosion process. Your ladder anchors will still fall victim as well as anything else metal within the splash zone. Oh and by the way, at this point its not a bad idea to mention that a light hosing down does a world of good in situations like these. Just take a hose after a heavy swim and spray down the top rails and the ladder and the lawn furniture and the decking (wood or stone). I was speaking to a gentleman on the phone today who reps one of the in-line zinc anodes commonly sold. They're now testing out whether or not battery-shaped steel cable, mounted under your top rail and bonded to the steel frame of your pool with the other end dangling into the water, when used in tandem with a traditional sacrificial disk or in-line anode system, would effectively quash rust issues with the pool entirely. That, as of yet, is still under analysis.

There are also reports coming out of Texas, most notably sited on http://thepoolbiz.blogspot.com, that there is a marked increase in damage being done to flagstone decking and coping. The science behind it is basically this: That when water rich in salt content is splashed onto something, especially something porous, that this salt water is absorbed. In time, the water from the equation evaporates and the salt is left within. I'm no scientist but from that point, crystallization occurs and can stain, discolor, and practically explode your stone from within.

So yes, discoloration to your plaster can occur if you choose to incorporate salt and electrolysis into your sanitation regimen. Yes, salt water provides for a much softer swim. Yes, salt water, in the long run is much cheaper to maintain chemically. And yes, is does have its disadvantages, as noted above. There are advantages and disadvantages to every system and chemical regimen out there. The key to navigating that path is knowing those pros and cons and choosing your course in spite of the fact. There's no cure-all method out there. There's no fill and walk away system out there no matter what someone may be trying to sell you.

In the end, this has all been leading to an end: The day your pool installs and the day you can first swim. The reward of choosing the right system for your unique needs, and knowing the potential consequences beforehand of any decisions you've made, and then bathing in the pleasure and status that comes along with ownership of an item such as your own pool.

[AlphaChaotic]

Richard,

Where are you getting your information that the recommended range of 1-3 ppm FC is incorrect? 4.5% of the CYA level which I prefer to maintain at 40 ppm? Quite interested in this...

Ashley

[chem geek]

Ashley,

Though I mostly concur with what you wrote about salt systems, I disagree with the part about galvanic corrosion with respect to titanium in the salt cell. Galvanic corrosion requires both electrical connectivity (adjacent metal touching or connected via a wire) and ionic (via an electrolyte) connectivity. The plates in the salt cell are not electrically connected to any other metal in the pool. You can read more about possible corrosion in salt pools in this thread where the primary increase in galvanic corrosion is due to the higher conductivity of the water and the higher chloride level has specific effects on stainless steel. I do demonstrate that IF there were even a small stray current leak from the electronics (i.e. an imbalance of current to each plate) then rapid corrosion could occur, but this is very speculative as it is not at all obvious how this would occur (especially if transformers are used to step down voltages).

Another minor point of disagreement is that though you could immerse a bonding-wire-connected zinc block into the pool water, that would (as you point out) introduce zinc ions into the pool which I believe is not a good idea as that can lead to staining. It is sufficient to bury the zinc block in moist (grounded) soil as the main point is to put a negative electric charge on the bonding wire to inhibit corrosion though I agree that such protection is not as strong as immersion which would result in corrosion of the zinc (i.e. more active protection vs. passive protection).

Most SWG manufacturers recommend 60-80 ppm CYA, not the 40 ppm CYA you prefer, and we've investigated the reason for this and determined that there is a non-linear relationship of CYA prevention of chlorine breakdown from the UV in sunlight. So even having a higher proportionate FC with the higher CYA results in a lower absolute FC loss per day at the higher CYA level. This lets one turn down the SWG for less on-time and that means less hydrogen gas bubble production which means less aeration and less outgassing of carbon dioxide. That reduces the rate of pH rise. So generally speaking, we recommend 60-80 ppm CYA for SWG systems as it prolongs cell life (since you don't have to run it as long) and has a more stable pH (so less frequent acid addition). This non-linear protective effect of CYA was first figured out by an experiment described in this post.

As for the chlorine/CYA relationship, you can take a look at this thread first two (or three) posts and then this post for the chemistry involved (you may need to click on the link field in your browser and press return -- it doesn't seem to link directly to it for some reason). The amount of disinfecting chlorine (hypochlorous acid) is roughly proportional to the FC/CYA ratio.

Richard

[Strannik]

First off, I suppose I should lay one blatant falsehood surrounding salt systems and "salt generators" and the like: A salt system is not a true alternative to a chlorine sanitizing regimen!

It's an alternative to dosing your pool with other forms of chlorine. As an added bonus - it breaks down chloramines when the water passes through the cell.

Another falsehood I hear repeated often enough is that employing a salt system and owning a salt water pool is markedly easier to maintain in comparison to chlorine.

Well let's see... Cleaning your cell once a month vs having to add chlorine daily... Really no change

SWGs are not designed to shock pools. While some manufacturers provide "superchlorinate" option it is not the same as shocking a pool, and it's recommended that when you do need to shock you use liquid bleach or similar.

However if your have to shock your pool it usually means that you didn't run your SWG on the correct setting.

In a nutshell, and according to the principles of galvanic corrosion, when two metals come into proximity to one another in an environment made active by the electrolysis process within the system, the corrosion will be drawn to the weaker of the two metals. Titanium, on the galvanic spectrum (remember titanium is used the cell of your salt chlorine generation system), is one of the strongest metals. So at that point most of the metal components of your pool (skimmer screws, light niches, ladder railings, etc.) would fall victim to the corrosion process.

In a nutshell - it's a big lie For galvanic corrosion to take effect - both metal parts need to be connected into one electrical chain and have a potential difference between them. I suggest that you don't just take the words from that blog as a gospel, but actually read about the process of galvanic corrosion

Your top rails will still fall victim to the corrosion process. Your ladder anchors will still fall victim as well as anything else metal within the splash zone. Oh and by the way, at this point its not a bad idea to mention that a light hosing down does a world of good in situations like these. Just take a hose after a heavy swim and spray down the top rails and the ladder and the lawn furniture and the decking (wood or stone). I was speaking to a gentleman on the phone today who reps one of the in-line zinc anodes commonly sold. They're now testing out whether or not battery-shaped steel cable, mounted under your top rail and bonded to the steel frame of your pool with the other end dangling into the water, when used in tandem with a traditional sacrificial disk or in-line anode system, would effectively quash rust issues with the pool entirely. That, as of yet, is still under analysis.

No need to wait for the results, i can tell you without any analysis - it won't work. Since there is no contact between anything above the water, and the water itself, there will be no galvanic corrosion occurring on anything above water - hence running a cable won't help.

Oh and a last touch: the reason galvanic corrosion actually occurs is because in USA all metal parts in a pool are required to be bonded together, in effect turning a pool into a large reservoir with electrolyte. In Australia we are not require to bond all parts together, hence galvanic corrosion is virtually unheard of.

[chem geek]

Strannik,

Thank you for clearing up some confusion I had as well since I didn't know that there wasn't the bonding requirement in Australia and that would indeed explain a lot with regard to far lower galvanic corrosion there even with SWG pools. The reasoning behind bonding is sound, assuming the deck is also properly bonded, in that it prevents stray voltages from shocking people, but it comes at a cost as you point out. Of course, it can be mitigated via a sacrificial anode (zinc, or if aluminum is bonded anywhere, then magnesium).

I didn't comment on the more general statements that were less technically oriented so I'm glad you did.

As for the top rails and ladders and other items that are not bonded, the problem is related more to salt accumulation and very high resulting conductivity which, along with moisture, results in standard traditional corrosion (i.e. not between dissimilar metals). This is more like the corrosion seen in this post though this was an extreme situation for several reasons: 1) it was an indoor pool with no CYA in the water so the effective chlorine concentration was very high (though the tracks only had splash-out and not constant exposure from immersion) and 2) the tracks are aluminum which appears to be more susceptible to corrosion from salt (perhaps a similar effect of chloride interfering with the formation of the passivity layer as is known to occur with stainless steel).

Other than rinsing off areas of splash-out to dilute the salt, I'm not sure how else to mitigate it other than using more robust materials (stainless steel instead of aluminum or steel).

I should also point out that the splash-out issues, as well as galvanic corrosion, are not unique to SWG pools. It's just that the rate or likelihood is higher due to the higher conductivity from the extra salt. Non-SWG pools have water that is conductive as well -- it's just not as much (usually less by a factor of 2-6 depending on the age of the water and type of chlorine that is used).

Richard

[chem geek]

(deleting duplicate post)

[Strannik]

As for the top rails and ladders and other items that are not bonded, the problem is related more to salt accumulation and very high resulting conductivity which, along with moisture, results in standard traditional corrosion (i.e. not between dissimilar metals).

Yup, that's exactly why i say that no analysis is needed, to tell that cabling won't help, since it can't mitigate chemical corrosion when there is no electrolyte present.

[azgirl]

It sounds as if you've found yourself a good pool store. Most pool sales professionals work on commission so for a salesman to take the higher road, and lay out the true pros and cons as he now knows them, so as to allow you to make an informed decision, isn't as commonplace as it should be. First off, I suppose I should lay one blatant falsehood surrounding salt systems and "salt generators" and the like: A salt system is not a true alternative to a chlorine sanitizing regimen! That theory rests on the foundation that salt, somehow, by its own nature is some kind of sanitizing agent. It, in fact, is not. It is true, however, that it is significantly different from the "traditional" chlorine-based regimen. The whole concept of salt water pools centers around electrolysis. Most salt systems are made up of two components: A cell (where all the magic happens) and the control panel (in most instances waterproof). The control panel provides information to the user/owner concerning your current salt content measured in ppm (parts per million), and the options to super-chlorinate and and internal timer allowing you to set the pump and filtration system to operate at two separate intervals in a 24 hour period. Some people, indeed run their pump 24 hours a day; it's just that I find two separate 6 hours periods in one 24 hour period to be just as effective and much less aggressive on the power bill. The cell will resemble a battery. Inside are usually 4 to 5 titanium disks. Now it needs to be understood that this cell installs between the pump and the filter. As water is returned to your pool, it passes through these titanium disks which are receiving a small electrical charge (depending on model, anywhere from 1-4 amps.)

The salt, which has already been added to the pool, in the meantime has been doing a little prep-work of its own. Once salt enters the water, it breaks down; one of those splits being an inactive chloride ion. That ion, mixed with the water, passed through the charged titanium plates, becomes active as well and then become an active chlorine ion. See: Chlorine Pool.

Another falsehood I hear repeated often enough is that employing a salt system and owning a salt water pool is markedly easier to maintain in comparison to chlorine. About the only thing I've found it to be easier on is the pocketbook. What these systems do for you is eliminate the need to utilize chlorine pucks and shock your pool weekly as part of a scheduled maintenance as set up by your local pool store. Its also not true that you never need to shock your pool when running a salt system. If algae gains a foothold in your pool and when even running your salt system at full capacity, you find yourself not being able to maintain a chlorine reading, it would at that point be necessary to shock your pool with a non-chlorinated shock, which tends to run a little higher than standard granulated chlorine. As well, you still to need to monitor and maintain proper alkalinity, pH, hardness and stabilizer levels. Doing so requires manually adding chemicals and re-treating if necessary. And thats why I say its not so much easier to maintain, just less costly to maintain. I find, on average, whereas you may spend 90 bucks a month on chemicals used to properly maintain a chlorine-based regimen, you'll find yourself on average, spending 20-25 dollars a month. Most systems can or nearly can pay for themselves in three years.

And then you get to the main disadvantage of a salt water pool and the original inquiry: The corrosion to your metal pool components caused by the electrolysis process that's tantamount to the system. It's going to happen! Let me repeat that: It's going to happen! Whether you have an above-ground pool or in; whether it be to metal pool components or to your brick coping or your concrete deck or your flagstone hardscape.... Yeah, you get the idea... Not what you've been hearing right? Well the truth of the matter is this: Your most widely used means of negating the corrosive nature of the charged salt content in the pool is the placement of a zinc disk or an anti-electrolysis weight, placed into or bolted in to your skimmer basket. These seem to be about 25% effective at protecting the metal components of your pool that sit below the water line. You can also ask your salesman about installing an in-line zinc anode. These, when properly installed and bonded into the system grid are 95%-100% effective at protecting metal components below the water line of your pool. In a nutshell, and according to the principles of galvanic corrosion, when two metals come into proximity to one another in an environment made active by the electrolysis process within the system, the corrosion will be drawn to the weaker of the two metals. Titanium, on the galvanic spectrum (remember titanium is used the cell of your salt chlorine generation system), is one of the strongest metals. So at that point most of the metal components of your pool (skimmer screws, light niches, ladder railings, etc.) would fall victim to the corrosion process. But by placing the zinc anode into the mix, you, in essence sacrifice that metal to the greater good of the pool. An added bonus: As it releases itself into the pool, it tends to coat the metal components present in the pool with itself to provide an even greater level of protection. So when properly changed, on average once every 6 months, you save yourself that hassle and get to focus on enjoying the pool itself and remembering the reason you signed up for all this anyway =)

At this point you'd probably be ready to sign on the dotted line. Right? But did you notice I mentioned several times before that those processes only protect the metals lying below the water level? Thats right: Your top rails will still fall victim to the corrosion process. Your ladder anchors will still fall victim as well as anything else metal within the splash zone. Oh and by the way, at this point its not a bad idea to mention that a light hosing down does a world of good in situations like these. Just take a hose after a heavy swim and spray down the top rails and the ladder and the lawn furniture and the decking (wood or stone). I was speaking to a gentleman on the phone today who reps one of the in-line zinc anodes commonly sold. They're now testing out whether or not battery-shaped steel cable, mounted under your top rail and bonded to the steel frame of your pool with the other end dangling into the water, when used in tandem with a traditional sacrificial disk or in-line anode system, would effectively quash rust issues with the pool entirely. That, as of yet, is still under analysis.

There are also reports coming out of Texas, most notably sited on http://thepoolbiz.blogspot.com, that there is a marked increase in damage being done to flagstone decking and coping. The science behind it is basically this: That when water rich in salt content is splashed onto something, especially something porous, that this salt water is absorbed. In time, the water from the equation evaporates and the salt is left within. I'm no scientist but from that point, crystallization occurs and can stain, discolor, and practically explode your stone from within.

So yes, discoloration to your plaster can occur if you choose to incorporate salt and electrolysis into your sanitation regimen. Yes, salt water provides for a much softer swim. Yes, salt water, in the long run is much cheaper to maintain chemically. And yes, is does have its disadvantages, as noted above. There are advantages and disadvantages to every system and chemical regimen out there. The key to navigating that path is knowing those pros and cons and choosing your course in spite of the fact. There's no cure-all method out there. There's no fill and walk away system out there no matter what someone may be trying to sell you.

In the end, this has all been leading to an end: The day your pool installs and the day you can first swim. The reward of choosing the right system for your unique needs, and knowing the potential consequences beforehand of any decisions you've made, and then bathing in the pleasure and status that comes along with ownership of an item such as your own pool.

[azgirl]

It sounds as if you've found yourself a good pool store. Most pool sales professionals work on commission so for a salesman to take the higher road, and lay out the true pros and cons as he now knows them, so as to allow you to make an informed decision, isn't as commonplace as it should be. First off, I suppose I should lay one blatant falsehood surrounding salt systems and "salt generators" and the like: A salt system is not a true alternative to a chlorine sanitizing regimen! That theory rests on the foundation that salt, somehow, by its own nature is some kind of sanitizing agent. It, in fact, is not. It is true, however, that it is significantly different from the "traditional" chlorine-based regimen. The whole concept of salt water pools centers around electrolysis. Most salt systems are made up of two components: A cell (where all the magic happens) and the control panel (in most instances waterproof). The control panel provides information to the user/owner concerning your current salt content measured in ppm (parts per million), and the options to super-chlorinate and and internal timer allowing you to set the pump and filtration system to operate at two separate intervals in a 24 hour period. Some people, indeed run their pump 24 hours a day; it's just that I find two separate 6 hours periods in one 24 hour period to be just as effective and much less aggressive on the power bill. The cell will resemble a battery. Inside are usually 4 to 5 titanium disks. Now it needs to be understood that this cell installs between the pump and the filter. As water is returned to your pool, it passes through these titanium disks which are receiving a small electrical charge (depending on model, anywhere from 1-4 amps.)

The salt, which has already been added to the pool, in the meantime has been doing a little prep-work of its own. Once salt enters the water, it breaks down; one of those splits being an inactive chloride ion. That ion, mixed with the water, passed through the charged titanium plates, becomes active as well and then become an active chlorine ion. See: Chlorine Pool.

Another falsehood I hear repeated often enough is that employing a salt system and owning a salt water pool is markedly easier to maintain in comparison to chlorine. About the only thing I've found it to be easier on is the pocketbook. What these systems do for you is eliminate the need to utilize chlorine pucks and shock your pool weekly as part of a scheduled maintenance as set up by your local pool store. Its also not true that you never need to shock your pool when running a salt system. If algae gains a foothold in your pool and when even running your salt system at full capacity, you find yourself not being able to maintain a chlorine reading, it would at that point be necessary to shock your pool with a non-chlorinated shock, which tends to run a little higher than standard granulated chlorine. As well, you still to need to monitor and maintain proper alkalinity, pH, hardness and stabilizer levels. Doing so requires manually adding chemicals and re-treating if necessary. And thats why I say its not so much easier to maintain, just less costly to maintain. I find, on average, whereas you may spend 90 bucks a month on chemicals used to properly maintain a chlorine-based regimen, you'll find yourself on average, spending 20-25 dollars a month. Most systems can or nearly can pay for themselves in three years.

And then you get to the main disadvantage of a salt water pool and the original inquiry: The corrosion to your metal pool components caused by the electrolysis process that's tantamount to the system. It's going to happen! Let me repeat that: It's going to happen! Whether you have an above-ground pool or in; whether it be to metal pool components or to your brick coping or your concrete deck or your flagstone hardscape.... Yeah, you get the idea... Not what you've been hearing right? Well the truth of the matter is this: Your most widely used means of negating the corrosive nature of the charged salt content in the pool is the placement of a zinc disk or an anti-electrolysis weight, placed into or bolted in to your skimmer basket. These seem to be about 25% effective at protecting the metal components of your pool that sit below the water line. You can also ask your salesman about installing an in-line zinc anode. These, when properly installed and bonded into the system grid are 95%-100% effective at protecting metal components below the water line of your pool. In a nutshell, and according to the principles of galvanic corrosion, when two metals come into proximity to one another in an environment made active by the electrolysis process within the system, the corrosion will be drawn to the weaker of the two metals. Titanium, on the galvanic spectrum (remember titanium is used the cell of your salt chlorine generation system), is one of the strongest metals. So at that point most of the metal components of your pool (skimmer screws, light niches, ladder railings, etc.) would fall victim to the corrosion process. But by placing the zinc anode into the mix, you, in essence sacrifice that metal to the greater good of the pool. An added bonus: As it releases itself into the pool, it tends to coat the metal components present in the pool with itself to provide an even greater level of protection. So when properly changed, on average once every 6 months, you save yourself that hassle and get to focus on enjoying the pool itself and remembering the reason you signed up for all this anyway =)

At this point you'd probably be ready to sign on the dotted line. Right? But did you notice I mentioned several times before that those processes only protect the metals lying below the water level? Thats right: Your top rails will still fall victim to the corrosion process. Your ladder anchors will still fall victim as well as anything else metal within the splash zone. Oh and by the way, at this point its not a bad idea to mention that a light hosing down does a world of good in situations like these. Just take a hose after a heavy swim and spray down the top rails and the ladder and the lawn furniture and the decking (wood or stone). I was speaking to a gentleman on the phone today who reps one of the in-line zinc anodes commonly sold. They're now testing out whether or not battery-shaped steel cable, mounted under your top rail and bonded to the steel frame of your pool with the other end dangling into the water, when used in tandem with a traditional sacrificial disk or in-line anode system, would effectively quash rust issues with the pool entirely. That, as of yet, is still under analysis.

There are also reports coming out of Texas, most notably sited on http://thepoolbiz.blogspot.com, that there is a marked increase in damage being done to flagstone decking and coping. The science behind it is basically this: That when water rich in salt content is splashed onto something, especially something porous, that this salt water is absorbed. In time, the water from the equation evaporates and the salt is left within. I'm no scientist but from that point, crystallization occurs and can stain, discolor, and practically explode your stone from within.

So yes, discoloration to your plaster can occur if you choose to incorporate salt and electrolysis into your sanitation regimen. Yes, salt water provides for a much softer swim. Yes, salt water, in the long run is much cheaper to maintain chemically. And yes, is does have its disadvantages, as noted above. There are advantages and disadvantages to every system and chemical regimen out there. The key to navigating that path is knowing those pros and cons and choosing your course in spite of the fact. There's no cure-all method out there. There's no fill and walk away system out there no matter what someone may be trying to sell you.

In the end, this has all been leading to an end: The day your pool installs and the day you can first swim. The reward of choosing the right system for your unique needs, and knowing the potential consequences beforehand of any decisions you've made, and then bathing in the pleasure and status that comes along with ownership of an item such as your own pool.

I am hoping to eliminate chlorine. I am wondering how the hydrogen peroxide alternative works alone or possible in conjunction with saline?? Guardian of Eden has information on

their website, they distribute the h2o2. Help! Thanks AZGIRL