5 reasons to use a Salt-Water Chlorination (SWC) system

[chem geek]

I have a 16,000 gallon pool with an electric opaque safety cover. The pool consumes no more than 1 ppm FC per day on average during the 7-month swim season with the pool used at least 5 days of the week. That's the big advantage with having an opaque pool cover -- minimal loss from sunlight and rock-solid pH from minimal outgassing and minimal water loss from evaporation.

My 12.5% chlorinating liquid costs me $3.60 per gallon including tax and 1 ppm FC takes about 2 cups for my pool and that's pretty much all I have to add all season long (i.e. no other chemicals). I only have to get a crate of 4 gallons about once a month and they reuse the bottles so there's no plastic waste. That's 26-1/4 gallons or about $95 per season. Electricity costs $0.32 per kilowatt-hour at our tier. The pool pump is a much bigger operating cost at $700 per year and that's after getting a Pentair Intellilo -- my previous pumps (including booster pump for a pressure-side pool cleaner) used to cost twice as much per year. My other high cost is use of the gas heater that extends the season (heating water through solar panels is done for most of the season).

If I were to get an SWG, it would primarily be for convenience, not cost savings, though I only have to add chlorine to my pool twice a week so it's not a big deal. Also, there is no free lunch and none of the downsides (most of which can be mitigated) of 3000 ppm salt pools were talked about.

Richard

 

[Strannik]

I have a 16,000 gallon pool with an electric opaque safety cover. The pool consumes no more than 1 ppm FC per day on average during the 7-month swim season with the pool used at least 5 days of the week. That's the big advantage with having an opaque pool cover -- minimal loss from sunlight and rock-solid pH from minimal outgassing and minimal water loss from evaporation.

My 12.5% chlorinating liquid costs me $3.60 per gallon including tax and 1 ppm FC takes about 2 cups for my pool and that's pretty much all I have to add all season long (i.e. no other chemicals). I only have to get a crate of 4 gallons about once a month and they reuse the bottles so there's no plastic waste. That's 26-1/4 gallons or about $95 per season. Electricity costs $0.32 per kilowatt-hour at our tier. The pool pump is a much bigger operating cost at $700 per year and that's after getting a Pentair Intellilo -- my previous pumps (including booster pump for a pressure-side pool cleaner) used to cost twice as much per year. My other high cost is use of the gas heater that extends the season (heating water through solar panels is done for most of the season).

If I were to get an SWG, it would primarily be for convenience, not cost savings, though I only have to add chlorine to my pool twice a week so it's not a big deal. Also, there is no free lunch and none of the downsides (most of which can be mitigated) of 3000 ppm salt pools were talked about.

Richard

Well in your case obviously there will be no savings. You would only need a chlorinator producing 5g/h to run for 1 hour/day, to cater for your chlorine needs. With chlorine demand that low, chlorinator indeed becomes just a convinience thing. I'm pretty sure there are plenty of other people in your position as well as a lot of people who require more chlorine and consequently chlorinator becomes financially viable for them. So far out of 3 people who actually did post their chlorine demand you are the only one who wouldn't benefit from SWG.

That's why i call everyone to do the calculations first, for their particular situation, rather than just say - "Reason 1 is invalid for US because i've read somewhere on the internet that electricity is expensive and bleach is cheap."

As i said numerous times before, the bigger the chlorine demand - the more savings you make.
If you use 0 chlorine - than there will be no savings whatsoever, only losses.

 

[SeanB]

You seem to be crossing the line between offering advice and making a sales pitch. :?

This has been hashed and calculated numerous times here and at other sites. As far as a being a strictly cost saving measure, buying and running a SWG is about a break even proposition. If you are considering getting one just to save money, then you will probably be disappointed in the long term. Having said that, however, the other advantages make them a great option for many people, including myself. My youngest daughter has fairly severe eczema so a SWG was a foregone conclusion for us. Sure, we could just ad salt to the water for the same effect, but I figure it I'm going to do that, I might as well get the added benefit of chlorine generation.

 

[Strannik]

You seem to be crossing the line between offering advice and making a sales pitch. :?

Why is that? Essentially i'm proving that my statement is a valid one. Which so far seem to be correct, with the only person making it invalid being chem_geek who has a very low chlorine demand due to using pool cover.

I'm not denying that there is a break even point until which SWG systems are not saving anything. This point will depend on your chlorine demand, electricity cost and capital cost for purchasing equipment.

This has been hashed and calculated numerous times here and at other sites. As far as a being a strictly cost saving measure, buying and running a SWG is about a break even proposition. If you are considering getting one just to save money, then you will probably be disappointed in the long term.

Again i have posted my calculations above. If there is a mistake in them - please point it out, i will be more than happy to amend them. If there is no mistake - please refer me to the other calculations which have been made numerous times, so i can have a look at them and see why they are different to mine.

 

[SeanB]

Here goes...

I try to be pretty understanding of people who are in the pool business who want access to the members here. We all have to make a living and this site is a great place for you to connect with potential customers and those potential customers can, in turn, benefit from your expertise. That is why I allow, and even encourage, users such as yourself to put a text link in their signature to their company or product. I only ask that you make helpful posts - helpful to the members of TFP, not yourself.

Each time you help someone you build credibility while at the same time, getting your link seen by hundreds of pool owners. It's a win/win. People who are "in the industry" who prove themselves over time are even given the rank of "Special Contributor." Trust me when I tell you that many, if not most, other sites do not allow that kind of free promotion. Your posts tend to lean toward self-promotion more than being geared toward helping users. That's my opinion, but it is my site, so I'm the one who gets to decide.

I don't need to post numbers for your approval and neither do any of the other members just because you are trying to prove a point that has been discussed numerous times before. So please, do contribute and offer helpful advice, but make a concerted effort to avoid even the appearance of self promotion. The funny thing is that the more you help others and don't promote your product, the more people will want to do business with you! It's a matter of establishing trust and building credibility. When you just pop in and start right in with a sales pitch, people see right through it - especially here...this site has some of the savviest pool consumers on the planet. :-D

Thanks,
Sean

 

[Poolsean]

Amen Brother!

 

[Strannik]

Ok here is a calculator:

http://www.tdconsulting.com.au/bleach1.php

Sorry i didn't have time to work on the design so it's a bit ugly.

You will need to know following information:

1. How much bleach you use daily.
2. How much gallon (or liter) costs
3. Concentration of bleach. (For Clorox - 6%, otherwise look on a drum label)
4. Cost of your chlorinator
5. Output of your chlorinator in grams per hour.
6. Cost of electricity.
7. Power consumption of your chlorinator.

After you do the calculations please copy+paste results here so we can compare.

 

[SeanB]

Here goes...

I try to be pretty understanding of people who are in the pool business who want access to the members here. We all have to make a living and this site is a great place for you to connect with potential customers and those potential customers can, in turn, benefit from your expertise. That is why I allow, and even encourage, users such as yourself to put a text link in their signature to their company or product. I only ask that you make helpful posts - helpful to the members of TFP, not yourself.

Each time you help someone you build credibility while at the same time, getting your link seen by hundreds of pool owners. It's a win/win. People who are "in the industry" who prove themselves over time are even given the rank of "Special Contributor." Trust me when I tell you that many, if not most, other sites do not allow that kind of free promotion. Your posts tend to lean toward self-promotion more than being geared toward helping users. That's my opinion, but it is my site, so I'm the one who gets to decide.

I don't need to post numbers for your approval and neither do any of the other members just because you are trying to prove a point that has been discussed numerous times before. So please, do contribute and offer helpful advice, but make a concerted effort to avoid even the appearance of self promotion. The funny thing is that the more you help others and don't promote your product, the more people will want to do business with you! It's a matter of establishing trust and building credibility. When you just pop in and start right in with a sales pitch, people see right through it - especially here...this site has some of the savviest pool consumers on the planet. :-D

Thanks,
Sean

In case you missed it the first time.

 

[Strannik]

Here goes...

I try to be pretty understanding of people who are in the pool business who want access to the members here. We all have to make a living and this site is a great place for you to connect with potential customers and those potential customers can, in turn, benefit from your expertise. That is why I allow, and even encourage, users such as yourself to put a text link in their signature to their company or product. I only ask that you make helpful posts - helpful to the members of TFP, not yourself.

Each time you help someone you build credibility while at the same time, getting your link seen by hundreds of pool owners. It's a win/win. People who are "in the industry" who prove themselves over time are even given the rank of "Special Contributor." Trust me when I tell you that many, if not most, other sites do not allow that kind of free promotion. Your posts tend to lean toward self-promotion more than being geared toward helping users. That's my opinion, but it is my site, so I'm the one who gets to decide.

I don't need to post numbers for your approval and neither do any of the other members just because you are trying to prove a point that has been discussed numerous times before. So please, do contribute and offer helpful advice, but make a concerted effort to avoid even the appearance of self promotion. The funny thing is that the more you help others and don't promote your product, the more people will want to do business with you! It's a matter of establishing trust and building credibility. When you just pop in and start right in with a sales pitch, people see right through it - especially here...this site has some of the savviest pool consumers on the planet. :-D

Thanks,
Sean

Well it's sad that you feel this way, but you are the owner so i have no choice but to comply.

The only thing i'm trying to sell in this thread is SWG technology in general. I don't really care which chlorinator people will buy after reading this thread, be it AutoPilot, AutoChlor, Zodiac, Aquarite or any of the other ones available on a market.

My main aim is to get them to make a decision to buy an SWG system.

If you think that no value can be added to this thread, feel free to lock it.

 

[SeanB]

You've missed my point. You're goal should not be to try to convince anyone to buy anything.

Providing information is one thing, but trying to "get them to make a decision to buy an SWG sytem," is not what this site is about.

At this point, I'm not going to lock the thread. Feel free to discuss calculations, but drop the agenda. You've made lots of helpful posts and I hope you will continue in that regard.

 

[Strannik]

You've missed my point. You're goal should not be to try to convince anyone to buy anything.

Providing information is one thing, but trying to "get them to make a decision to buy an SWG sytem," is not what this site is about.

Ok now i got you.

Well calculator is up there, anyone who wants to know what the costs of owning an SWG system are can use it, and i will leave this thread alone.

 

[JasonLion]

Cool calculator!

I don't disagree with SeanB, but I do really want to know how the costs for a SWG work out. Can we stick to the "this is what I calculate" part and not go into the "this is what you should do" aspect? In my view, the goal of the site is to share information and then let each person decide for themselves. My earlier comments were based on a two year old conversation at the Pool Forum. It is interesting to update the numbers for current SWG, bleach, and electrical prices.

The calculator appears to assume that every day of the year is a swimming day. It would be nice if there was a number of swimming months in the swim season field to adjust for the fact that most people close the pool for the winter. Also, keep in mind that many of the inputs are not things most people will be able to figure out. For example, grams of chlorine per hour from the cell required some digging to figure out, and I know where to look.

I have an AutoPilot Total Control system with an SC-60 cell, but I am going to pretend that I have the AutoPilot Digital model to make a fairer comparison. Deep discount Internet price is around $1000. The Digital model is one of the fanciest models on the market, with "all the bells and whistles" as you say.

Bleach costs me $1.33 per gallon for 6% (5.75% trade).
I use about 0.75 gallons a day during the summer, correcting for my 5 month/year swim season that averages out to .31 gallons per day over the course of a year.
My electricity is around .13 per KWh
As best I can figure out the SC-60 cell puts out 37 g/hour
The unit is rated for 3 amps at 115 volts, which comes out to about .345 KW, although actual usage is probably lower

Using the new calculator to estimate costs over 5 years I get:

Bleach $747
Electricity $149
Unit $1000
Loss of $401

Interest on a five year loan (to purchase the unit) for $1000 at 8% works out to an additional cost of $217
Muriatic acid to compensate for PH rise (4 gallons per season) would be an additional $100 over 5 years.

Total cost of the SWG over 5 years is $1466, or $718 more than bleach.
The second five years would be $709, or a savings of $38.
(Assuming it needs a new cell after 5 years, replacement cell is around $460 plus interest.)
Additional cost beyond bleach over 10 years is $680.

Or course I could have gotten a different SWG with the same capacity that would have cost noticeably less. My rough estimate is that I could break even using one of the less expensive brands.

Despite this calculation, I am totally pleased with my SWG. Cost is only one of several factors that entered into my decision to buy it. For me the crucial factor was connivence. The pool can be ignored for a couple of days at a time, which is worth far more to me.

 

[Strannik]

Cool calculator!

Thanks!

The calculator appears to assume that every day of the year is a swimming day. It would be nice if there was a number of swimming months in the swim season field to adjust for the fact that most people close the pool for the winter. Also, keep in mind that many of the inputs are not things most people will be able to figure out. For example, grams of chlorine per hour from the cell required some digging to figure out, and I know where to look.

I can probably insert the months field, however it's going to be hard to go away from grams/h, because it's needed to calculate how long the chlorinator actually has to run to produce equivalent amount of bleach.

I have an AutoPilot Total Control system with an SC-60 cell, but I am going to pretend that I have the AutoPilot Digital model to make a fairer comparison. Deep discount Internet price is around $1000. The Digital model is one of the fanciest models on the market, with "all the bells and whistles" as you say.

Bleach costs me $1.33 per gallon for 6% (5.75% trade).
I use about 0.75 gallons a day during the summer, correcting for my 5 month/year swim season that averages out to .31 gallons per day over the course of a year.
My electricity is around .13 per KWh
As best I can figure out the SC-60 cell puts out 37 g/hour
The unit is rated for 3 amps at 115 volts, which comes out to about .345 KW, although actual usage is probably lower

Using the new calculator to estimate costs over 5 years I get:

Bleach $747
Electricity $149
Unit $1000
Loss of $401

Here is something i don't understand:

Results for: chlorinator
100% Chlorine output: 37 gram/hour
100% Chlorine usage: 70.2 gram/day
Chlorinator running time: 1.8972972973 hours
...

You have a chlorine demand of 70 grams/day. Yet you have a chlorinator which is capable of making 888 gram/day
May i ask what was the reason behind choosing this particular model and not something with lower output?

Interest on a five year loan (to purchase the unit) for $1000 at 8% works out to an additional cost of $217
Muriatic acid to compensate for PH rise (4 gallons per season) would be an additional $100 over 5 years.

Total cost of the SWG over 5 years is $1466, or $718 more than bleach.
The second five years would be $709, or a savings of $38.
(Assuming it needs a new cell after 5 years, replacement cell is around $460 plus interest.)
Additional cost beyond bleach over 10 years is $680.

Or course I could have gotten a different SWG with the same capacity that would have cost noticeably less. My rough estimate is that I could break even using one of the less expensive brands.

Despite this calculation, I am totally pleased with my SWG. Cost is only one of several factors that entered into my decision to buy it. For me the crucial factor was connivence. The pool can be ignored for a couple of days at a time, which is worth far more to me.

Well you see this is where (in my opinion) convenience starts. Pool Pilot is equipped with digital salt meter, and ORP controller(correct me if i'm wrong here).

So essentially for the price of $1000 you get: Chlorinator + Salt meter + ORP Controller. Now i don't know about US, but our pool shops don't supply those with say every 10th drum of bleach. So to be comparing apples with apples we need to somehow subtract the cost of those, from the cost of chlorinator.
In that case we would know true cost of chlorination, and a cost of convenience added to it.
That's just my view on it.

 

[JasonLion]

I have the top of the line AutoPilot Total Control system, which cost me about $2600. It includes ORP, a PH meter, and an acid tank with peristaltic pump. I got the large and fancy system for three reasons. I wanted something that my family can deal with as easily as possible when I am away on business trips. We are planning to replace the pool with something much larger and fancier in a year or two, so this was an investment in the future pool. And third, I love to play with fancy technical toys with all the options.

When I did the price comparison above I was comparing to the AutoPilot Digital system. It has a salt meter, temperature meter, fancy alpha numeric display, etc, but no ORP and no acid tank/pump. Some kind of salt meter is almost universal in SWG systems. They don't all have readouts in ppm, which the higher end AutoPilot systems have, but they all measure salt one way or another.

My current pool would probably be just fine with a Pentair IntelliChlor IC 20, about $510 (Internet deep discount) with about 13 grams/hour. And it would offer nearly as much day to day connivence as the PoolPilot Digital system but without the "bells and whistles". That would save $490 in purchase price, $107 in interest, and about $50 in electricity, which would put it far closer to break even after five years and well ahead after 10 years.

All of this reminds me of another factor. When using bleach you need to test the FC level more frequently. Probably about $10/year for the extra reagents. Though most people buy a kit with plenty and probably don't use up their reagents and so simply end up throwing out the excess after one to three years, which would mean no price difference.

 

[Strannik]

I have the top of the line AutoPilot Total Control system, which cost me about $2600. It includes ORP, a PH meter, and an acid tank with peristaltic pump. I got the large and fancy system for three reasons. I wanted something that my family can deal with as easily as possible when I am away on business trips. We are planning to replace the pool with something much larger and fancier in a year or two, so this was an investment in the future pool. And third, I love to play with fancy technical toys with all the options.

When I did the price comparison above I was comparing to the AutoPilot Digital system. It has a salt meter, temperature meter, fancy alpha numeric display, etc, but no ORP and no acid tank/pump. Some kind of salt meter is almost universal in SWG systems. They don't all have readouts in ppm, which the higher end AutoPilot systems have, but they all measure salt one way or another.

My current pool would probably be just fine with a Pentair IntelliChlor IC 20, about $510 (Internet deep discount) with about 13 grams/hour. And it would offer nearly as much day to day connivence as the PoolPilot Digital system but without the "bells and whistles". That would save $490 in purchase price, $107 in interest, and about $50 in electricity, which would put it far closer to break even after five years and well ahead after 10 years.

All of this reminds me of another factor. When using bleach you need to test the FC level more frequently. Probably about $10/year for the extra reagents. Though most people buy a kit with plenty and probably don't use up their reagents and so simply end up throwing out the excess after one to three years, which would mean no price difference.

Fair enough. As i said above, for people with low chlorine demand it doesn't make financial sense to buy SWG.

Now lets view a pool with a chlorine demand 5 times more than what you have. Would you agree with me that SC-60 will still manage such demand with no problems?

Results for: chlorinator
100% Chlorine output: 37 gram/hour
100% Chlorine usage: 340.8 gram/day
Chlorinator running time: 9.21081081081 hours
Costs (over 5 year period)
Bleach cost: $3628.1
Electricity cost: $753.916378378
Equipment cost: $1000
_______________________
Total savings: $1874.18362162

As you can see a person with such a pool would have significant savings over bleach.

The point i'm trying to reiterate over an over is that for every combination of pool/chlorinator there is break even point beyond which chlorinators become viable option. Obviously for some combinations this point will be unreachable because of limited life of the cell. Consequently for those people the main consideration becomes convenience.

 

[JasonLion]

It is simpler to read the thread if you are more selective about what you quote. Quotes can be handy when you are responding to several people or when responding to a small section of an entire post. Simply quoting the entire previous message makes the thread more difficult to read.

Yes, I clearly see that using the current method of estimating costs that larger chlorine demands result in better economies for SWGs. However that suggests to me that there is a factor we aren't taking into account properly.

In the preceding discussion both of us have used the assumption that the cell will last for five years. I know that the actual cell life depends on a number of factors. Based on user reports, five years is a reasonable first approximation. However, assuming that chemistry is maintained ideally, the install is done properly, and there are no manufacturing/materials problems, my understanding is that cell life is proportional to the number of hours the cell is active and not to the total amount of calendar time that passes.

If cell life depends on the number of hours it is turned on, then a single cell will be able to create a more or less fixed amount of chlorine over it's lifetime (all other factors being constant). Thus a pool with low chlorine demand will allow the SWG to last longer (and so be more economical than your model), while a pool with higher chlorine demand will wear out the same cell relatively quickly (and so be less economical than your model). If this is correct, it will require changes to your model and may affect the final conclusion.

 

[Strannik]

... my understanding is that cell life is proportional to the number of hours the cell is active and not to the total amount of calendar time that passes.

If cell life depends on the number of hours it is turned on, then a single cell will be able to create a more or less fixed amount of chlorine over it's lifetime (all other factors being constant). Thus a pool with low chlorine demand will allow the SWG to last longer (and so be more economical than your model), while a pool with higher chlorine demand will wear out the same cell relatively quickly (and so be less economical than your model). If this is correct, it will require changes to your model and may affect the final conclusion.

Yes you are correct. Cell anode life is a function of load and time it's under load, assuming water properties are the same.
Consequently running a large cell on a small pool like you are doing for example will allow it to last longer, than if it was running on a larger pool. Moreover as far as i remember (although don't quote me on this) this dependency is non-linear.

The problem with including this into my model is that the electrodes are not made of the same materials. There is a handful of manufacturers of quality anode in Australia, Europe and USA. And then there is a cheap low quality anode made in India and China.

Now to build a proper model i would need to know which chlorinators use which anode, and this information is usually kept secret by most manufacturers.

Moreover, if we narrow it down to quality anode - each manufacturer makes anode with different characteristics.

For example:

Anode A

life - 5 years
Load - 20A, 8 hours a day.

Anode B

life - 5 years
Load - 20A, 24 hours a day.

So effectively same company can use different material in different cells and there is no way to find this data out.

 

[EskimoPie]

You've missed my point. You're goal should not be to try to convince anyone to buy anything.

Providing information is one thing, but trying to "get them to make a decision to buy an SWG sytem," is not what this site is about.

At this point, I'm not going to lock the thread. Feel free to discuss calculations, but drop the agenda. You've made lots of helpful posts and I hope you will continue in that regard.

I really have to side with Strannik on this... I don't feel at ALL like he's trying to push people to buy anything from him, he feels strongly about SWCG and is making a case for that (A very convincing case I might add). Many people have said that the 'it's a wash' or it's not a matter of cost, just convience and he posted numbers and calculations disagreeing with that. There are obviously different ways to manage your pool sanitization and he's making a case for what he feels is the better method. I honestly don't feel like the BBB crowd is being fair here.

Most people come here as newbies (as did I) to learn about how they should manage their pool... IMHO, Strannik was simply laying out an argument (supported by numbers) that showed a SWCG is a cheaper way in the long run for many people. Why do I feel like this is becoming so personal for many people?

 

[j4ydubs]

You seem to be crossing the line between offering advice and making a sales pitch. :? .

I've found Strannik informative and helpful. I don't feel he's trying to sell me anything. Just trying to explain a benefit (cost) of SWCG that others have stated isn't true. He's backed up his statement with numbers, but I haven't seen the other side do that.

This has been hashed and calculated numerous times here and at other sites. As far as a being a strictly cost saving measure, buying and running a SWG is about a break even proposition.

I'm new to the site, so I don't have the benefit of having read those threads. Can you point me to one that concludes a break even? Thanks.

John

 

[chem geek]

As is often the case with any sales argument, it is not so much what is said that is the issue (though sometimes it is), but rather what is not said. Virtually every offering has both pros and cons, but sales pitches only talk about the pros and not the cons. Higher salt levels that are 2-6 times what are normally found means 2-6 times the conductivity of the water to electrical (ionic) current and that has implications that may need to be mitigated. Splash-out of salt has other implications that may need to be mitigated. This has all been discussed elsewhere. The point is that balanced discussions don't just talk about the pros.

A calculator that computes the cost component for comparison is great. Giving one-sided arguments for going with SWG without any warnings of items to be mitigated can lead to problems, as we have seen with a small number of pools.

Richard