Actual SWG vs. Bleach Cost, Eye popping!

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New2Me

New2Me

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Jun 2, 2008
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SW Indiana
Having read here, there, and everywhere how MUCH a SWG was going to save me, I mulled it over, ran some numbers in my head, and decided to pull the trigger on getting one. I went low budget (thankfully), and now I am almost kicking myself for not running ALL of the numbers first, `cause I'm paying $2.55 per equivalent gallon of 6% bleach!!! :evil: How did I get here? Well, it certainly wasn't with vague numbers from sales literature; you have to dig for the fine print.
Some background- after swearing off 3 inch stabilized chlorine tabs (CYA~100) in my auto-feeder, I got a test kit(that was actually first!) and started dosing with Wal-Mart Ultra bleach at $1.68/G, then switched to supermarket Alway-Save brand for $0.99/G. I need about 1/2 gallon/day(~64 oz.) for my 24,000 gallon water feature (almost NO bather load, we sit inside and look out at it 8) ) I still wasn't comfortable with popping up to a grand for a SWG, so I dug for the truth on ACTUAL performance of the various SWG's, in units of chlorine generated per hour, looking to get my needed 64 oz bleach/day in my 10 hour daily pump run time. I went with an Intex A/G Krystal Kleer system I got new on Ebay for $157(including S&H! :-D ), because it generates ~12 oz of 6% Bleach/Hr, meaning I would run it 5-6 hours/day, and I could install it with out re-plumbing. I have ran it 6 hours/day, taking a few days off when my FC was too HIgh. I also plugged it into a Kill-A-Watt meter to see how much energy it actually takes to run, and have kept track of it. Here is my cost breakdown-

SWG Capital Cost $157.00
Salt Capital Cost $63.70
Electric Rate $/Kwhr $0.11 (we're surrounded by coal burning power plants, paying with our health)
Electric Consumed, Kw/Hr 0.1658
Eq. 6% Bl Rate/Hour in Oz. 12 (1.24 chlorine pounds/day max. converted, Thank You! JasonLion)
Expct Cell Life 1000
Gallons of 6% over lifetime 93.75
Lifetime Cost / Gallon $2.55

This is a one year cost, based on (a hopefully worst-case)1000 hour cell life. If my electric rates don't go up, and the cell lasts for another year (it has a two year warranty), my Lifetime Cost/G drops to $1.37, a third year will drop it to $0.98, a fourth to $0.78, and (I'm praying for this :wink: ) at 5 years to $0.67. Note that if I replace the cell once(@$157) my 5 year cost goes to $1.00. I did not include ANY installation cost, as I have a removable set-up. Am I going to keep it? Yes, I have already spent the money. I could have spent $800 for a lower end NAME brand SWG with a 5 year cell life, and paid $2.04/G, or $1500 for a high-end model with a 10 year warranty and paid $1.86/G, so I'll be happy to get two years. If I were fortunate/unfortunate? enough to live in a nicer climate where electric rates are ~$0.30/KwHr those last two numbers would be $2.37, and $2.20.
As to claims that SWG are cheaper than bleach- NO WAY, unless they last a LONG time! Convenient-YES, if you can figure out how to use them.
My assumptions are that these systems have the same power/chlorine conversion efficiency, no installation cost, no transport cost for getting bleach,no bonus for convenience. For those that want pool chemistry numbers-
FC= 7.0, FAS-DPD 10ml sample
CC=0
TC=7.0
Ph=7.5
TA=90
CYA=80-90
CH=170
Borates=45
Oh, yeah, I also didn't account for MA addition for Ph control due to SWG. Tabs drove Ph down, bleach was neutral, and it keeps creeping up now. :(
I hope that my experience helps those on the SWG fence to feel more at ease, waiting for the NAME brand capital cost to drop, or going low budget, is in my opinion, very prudent.
 
Not intending to take this to the Agree to Disagree room, but .... who said it was cheaper?

If you EXCLUDE the initial cost of the system, there's a chance that it may be because you're spending money on salt and acid, rather than chlorine tabs/bleach/cal hypo/dichlor, pH balancer, and shock treatments.

The cost issue had been discussed several times before.
 
Everyone's situation is different, so let's see why the economics don't work very well in your case. I assume below only bleach cost since you don't shock frequently and the pH is stable.

Your bleach cost is around 50 cents per day. Your electricity cost is around 6 * 0.1658 * 0.11 = 11 cents per day. So you are saving around $11.70 per month. The break-even point with SWG and salt capital costs is ($157 + $63.70) / $11.70 = around 19 months. The 1000 hour cell life at 6 hours per day translates to 5-1/2 months which is very, very short and is probably why this particular SWG cell is so inexpensive. Even excluding the salt cost which is one-time (compared to SWG cell replacement), the break-even point is $157 / $11.70 = around 13 months so still not worth it economically unless the 1000 hour cell life estimate is way off.

So if the cell life is as short as 1000 hours, then yes the economics don't pan out very well.

Higher quality (and higher output) SWG cells last longer in the 3-5 year range but are also more expensive. If one was $1000, then the break-even point would be 90 months which is beyond even a 5-year live.

The reason the economics do not work well in your pool is that the daily chlorine usage is fairly low at around 1.3 ppm FC per day. This may be because you don't use the pool very much and may also be due to the amount of sunlight exposure. Generally, the chlorine usage rate needs to get to at least 2 ppm FC per day before the ongoing economics pan out AFTER the initial installation. That is, the cost for cell replacement is lower than initial installation. So the first 3-5 years you don't save much and might lose, but after that you save some.

Generally speaking, people do not buy SWG systems for lower operating cost, but rather for the convenience. As Sean mentioned, this has been discussed in other threads. You don't generally buy an SWG to save money if you're comparing against BBB.

Richard
 
Making a one year comparison is misleading. Every SWG made should last at least two seasons, and nearly all of them will last longer than that. A five year lifetime with one cell replacement during that period sounds like the most likely long term outcome to me.

This subject was explored extensively in this topic. Depending on the size of the pool and just which factors you want to take into account, we came up with fairly small cost savings through small extra expenses for a SWG.
 
Here is my experience.

I started with trichlor till I got into trouble with a high CYA. Switched over to BBB. It was very labor intensive for me. Hauling the bleach down to my pool everyday was a pain in the neck. Installed a Liquidator. Was a little less labor intensive but required a lot of maintenance and tweaking. So I installed a SWG. It has been the most convenient method by far. I check the chemistry once a week. Feels nice on my skin. That's it. I am happy. Its probably more expensive than the other options but as far as I am concerned based on my own setup and preferences the SWG has been awesome and worth the cost. Clearly though it is not the best option for everyone.

Just my 2 cents,.
 
This post started from a discussion with pool owning friends on Labor Day over why I had a SWG, and not the Liquidator that I was talking up on Memorial Day, and didn't get. I followed the posts on the WS and other troubles that people were having with the Liquidator, and DLSDO, your SWG install looks great, I'm glad that you're happy with it! My feeling was that the SWG would be cheaper than Liquidator/BBB( and Poolsean, you're right, I don't know IF anybody said it would be) but I was surprised at how the numbers came out. I used the 1000 hours to start somewhere near my operation needs; Intex gives a two-year warranty but has a FAQ that answers the cell life question by stating that each pool chemistry is different, and greatly affects it. I expect to get at least two seasons, three and I'll be thrilled. Where BBB and SWG both shine is when compared to an auto-feeder stuffed with tabs, weekly algaecide dose and use of powdered chlorine to shock weekly. My friends liked my weekly BBB savings vs. tabs($3.50 vs. $12), and wanted to know what the SWG was costing, so I crunched it and posted it. I was thinking that less than 84 cents/week for my CL needs was great, like I said I was shocked at what the up front costs do to the payback. I have seen several posts wanting info on SWG costs, I've supplied mine.
 
Cost of SWG - $1200
Cost of salt and acid for 1 year - $60
Convenience factor of being able to ignore your pool for a week or more at a time and KNOW it will be perfect - PRICELESS!
 
New2Me, to save you calculations next time, there is a link to a cost calculator in my signature ;)
Generally SWG is not cost effective for pools with small chlorine demand, and extremely cost effective for large commercial pools.
Savings of some of our commercial clients run into hundreds of thousands dollars across 5 year period.
 
Being an owner of a Liquidator and purchasing my 6% bleach from Sams I will provide my cost of ownership so far. I have been using the BBB method since we built the pool and it open in November 2007. Total cost of bleach since Jan 2008 until today is $91.23. We had a record hot summer here in Texas this year which ate up a lot of chlorine. Add to this the cost of the Liquidator. Last weekend, was the first time that I cleaned out the Liquidator. For me, the Liquidator is as good as it gets. Up to just a few weeks ago, I use to test daily. I have so much confidence in my Liquidator and pH Adjuster that I test now twice to three times a week.

Question, what is the actual life span of a SWG? How long is the manufacturer warranty? No spin, just wondering. Will the SWG last longer then 6 years in a hard water enviroment? (We have plenty of hard water in my area.)

As my costs trends, it looks like I might be able to end the season in December 2008 to be under $150 for bleach. From what I can tell, basic costs of a SWG is around $1200 not to include salt and other costs. Let's say my cost per year is $200 on bleach (Prorate the Liquidator into the $200). To break even on just the SWG, the SWG will need to last 6 years. Will the SWG last longer then 6 years? Anyone have a SWG that is older then 6 years?
 
Strannik-Thanks for the link, the calculator does make it easy!
Sabot- I'm glad that the Liquidator is now working for you, and for all of those that are using, and fine tuning it. Like I said before, I was telling people that I was going to get a Liquidator, but then started looking at the mods people were doing with 1/4 -> 3/8 lines, valve/fitting upgrades, and WS flow restrictions, plus my limited pad space and I backed off, DLSDO's switch to a SWG really got me. I looked through all of the post that I could find here about SWG's, and then did searches on the net, too. When I found the actual generation ability of the different cells, and saw what my pool was going to require in its present state, I realized that the Intex would work. And it has! Since it was far more inexpensive than most SWG's- about the same as a Liquidator, I thought that I would really be saving some green, hence my surprise at the actual cost. I too am interested to hear about cell life from actual users(particularly Intex users.) The net is full of people having problems with this Intex, but it probably also is the most installed SWG in the US, and most posts seemed to come from people that would have problems with setting a clock! The net, and this forum is also full of problems with the other SWG's, so I wasn't too worried about the Intex posts; reading the positive posts here from MikeinTN and NWPoolmom re-assured me. I also have admiration for the service advice that Poolsean and the others are able to provide SWG users.
waterbear- I wouldn't ignore the pool for a week! Electricity is like water, it'll show up where you don't want it, or it won't when you will. Either way, bad things can happen quickly!
Other than the cost, which will be OK if it lasts, my only other knock on the Intex is the clock is a little fast, tho' it is simple enough to program that I can adjust for it. :)
I'm also curious as to how other SWG users super-chlorinate; I've got boxes of bleach on hand from when I was going BBB, and plan to use it to shock, but I'm wondering what the shelf life will be in the garage over winter. Hopefully it'll still be good enough to open with in the spring, and BBB me over till when the water is warm enough to run the SWG.
 

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Being a novice pool owner with about a year of ownership under the belt, I am beginning to understand that chemicals and the water itself are hard on equipment. Seems that most equipment is expected to last a few years of continuous use. For me, I don’t close my pool. The pump runs year around but not as long during the off season. For me, if my Liquidator lasts two seasons without splitting wide open then I will be very happy. I will take it off line and store it before the first hard freezes (Nov/Dec). Last year we where still swimming in November due to the solar heater.

Back to the point, have a system which is a consumable does not appeal to me. (I am knocking on wood here…lol) This is not a dig on anyone. For me, electricity is by far the largest expense. (Thanks to BBB, chemicals are not.) If things go well, I want to purchase a variable speed pump to replace my 2hp single speed pump. I will move the single speed pump to pump just the water features. The hard water is dirt cheap compared to the electricity. I am trying to get the HOA to allow me to install a windmill farm!

I am still very interested in how long the SWG lasts.
 
Sabot said:
Question, what is the actual life span of a SWG? How long is the manufacturer warranty? No spin, just wondering. Will the SWG last longer then 6 years in a hard water enviroment?
Click to expand...

Everything except the cell should last 10 or 15 years. However, some models seem to have problems with lightning and others seem to have trouble with the flow switch. Also, SWGs haven't been around long enough to confirm that. That estimate is based on the lifetime of similar electrical/electronic devices. A SWG cell typically lasts two to five years, depending on water chemistry and usage. If hard water leads to scaling the cell life can be somewhat reduced.
 
Poolsean said:
Not intending to take this to the Agree to Disagree room, but .... who said it was cheaper?

If you EXCLUDE the initial cost of the system, there's a chance that it may be because you're spending money on salt and acid, rather than chlorine tabs/bleach/cal hypo/dichlor, pH balancer, and shock treatments.

The cost issue had been discussed several times before.
Click to expand...

While I don't think anyone here has claimed SWG is a way to save money, the pool stores around me certainly make that claim. "Save money on chemicals! No need to ever buy expensive chlorine again!" etc.

When I first investigated the purchase of the SWG at the pool store, the guy told me it would be convenient and it would be cheaper than buying chlorine. Until then, I was spending about $100-150/year on chlorine pucks. The guy then told me I'd need to replace the cell on the SWG every 3-4 years at $600. When I pointed out that that would mean I'm still paying the same annual costs, not to mention the initial $1000+, he said, "Yeah, it's not any cheaper, but you still get the convenience." :roll:

I ended up buying online and installing it myself for a significant savings as convenience was the main motivating factor. Also, I like not storing chlorine.
 
New2me - Best way to super-chlorinate is to add bleach. I don't know if your stockpile will make it over the winter or not. Best thing to do would be to test it come spring, and see what it's concentration is. I'll use bleach to raise my FC to shock level when I close the pool, and again in the spring if needed. Your Intex might be able to generate enough FC eventually to reach shock level (especially if the pool is covered), but that's mighty hard on the cell.
 
We have customers with SWGs they have purchased over 25 yr ago, still going strong (with cell replacements of course).
Generally the more basic chlorinators will outlast high-end stuff with bells and whistles because there is less room for failure. That of course assuming they are of comparable quality, low quality stuff will fail early regardless.
 
Roughly speaking, though, the replacement units for the typical 10,000-20,000 gallon residential pool for a high quality system that had an initial cost in the ballpark of $1000 will be in the neighborhood of $300. But as Strannik says, it depends a lot on model and manufacturer. Nevertheless, it's a lot less for the replacement than the initial installation for the ones that last 3-5 years so the biggest capital cost is that initial installation.
 
Can cell plates be re-coated? It seems to me that all these things are metal (platinum?) plates coated with some higher priced (rubineum?) metal. Can I take 'em to my local chrome shop and get them re-done? Or have the local metal shop cut some new ones( after hacking the container apart)?
 

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