Thinking of converting to SWG

[JFox762]

I have a few questions.
Pool size is 15,000 Gallons and it is a plaster pool. I live in the Phoenix Metro area.

How difficult is it to install the conversion myself?
What brand generator is recommended?
How long do the salt cells last for?
What size system should I get? I've read that you should deliberately oversize it.
How much money could I expect to save vs Chlorine?
Does the system produce CYA?

Is it a mostly hands-off process of maintaining chlorine levels?
I can be pretty bad about staying on top of adding chlorine too the pool/shocking the pool as I am quite forgetful.
I know you still need to stay on top of acid levels.

 

[Bperry]

I have a few questions.
Pool size is 15,000 Gallons and it is a plaster pool. I live in the Phoenix Metro area.

How difficult is it to install the conversion myself?
What brand generator is recommended?
How long do the salt cells last for?
What size system should I get? I've read that you should deliberately oversize it.
How much money could I expect to save vs Chlorine?
Does the system produce CYA?

Is it a mostly hands-off process of maintaining chlorine levels?
I can be pretty bad about staying on top of adding chlorine too the pool/shocking the pool as I am quite forgetful.
I know you still need to stay on top of acid levels.

The circupool line is setup for DIY install and isn’t hard with basic plumbing and electrical skills.

Cells last differing amounts measured in hours of run time. Depending on how much chlorine you need it should last 5+ years if the water quality is maintained.

You should get one for double your pool size. The sizes they reference are based on making chlorine full power 24x7 and you don’t need to do that.

It only converts salt into chlorine, it doesn’t produce CYA.

It’s not hands off but still requires you to test the water a few times per week like any other chlorination method it is the most hands off option there is. Once it’s somewhat dialed in, you’ll just need to adjust the output power a few times per season.

TFP is a very specific pool care strategy and is easy to do once you’re used to it as long as you have your own recommended test kit. Welcome!

 

[Newdude]

Hey J and Welcome !!!

How difficult is it to install the conversion myself?

You need basic plumbing and electric skills. The electric is harder to learn on the fly, and potentially dangerous if you're a true beginner.

How long do the salt cells last for?

The flagship cells are rated for 8k to 10k hours of use. A unit 'sized' for your pool needs to run 24/7, reaching those hours sooner than a 2X which only needs to run 12 hours to produce the same chlorine. I'd buy 3X and strongly consider a 4X in your long, hot climate. The upgrade is far cheaper than the lifespan gained by only running a 4X cell 6 hours a day.

How much money could I expect to save vs Chlorine?

Depends how big you oversize it. Let's go with 3X, a Circupool RJ45. It'll make 16 FC per day in 15k gallons or 6666 lifetime FC if it lasts 10k hours. (They claim 15k, so I'm being extra conservative in my estimate). It'll cost you $1546 with tax, and let's call it almost double with a full pro install at $3k. (Again, conservative). That's $0.45 per FC, and replacement cells will be in the low 20 cent range per FC.


1 gal of 10% chlorine makes 6.7 FC in 15k gallons.

$5 jug = $0.74 per FC
$6 jug = $0.89 per FC
$7 jug = $1.04 per FC.

RJ45 = $0.45 per FC full install
RJ45= $0.30 @ $2k DIY (for install parts)

I'll note that the Walmart PE chlorine that most use is a little over $6 per gallon after tax. Lowes was $7+ and HD was $9+ for most last summer.

Anywho, even paying through the nose for pro install, you'll make out approaching a 2x ROI. With replacement cells, you'll approach a 4X ROI.

Is it a mostly hands-off process of maintaining chlorine levels?

It adds what you tell it to add, daily. Each adjustment is good for 2 to 6 weeks. You have to watch for the next adjustment time by testing.

 

[SJPoe]

I have a few questions.
Pool size is 15,000 Gallons and it is a plaster pool. I live in the Phoenix Metro area.

How difficult is it to install the conversion myself?

If you are at all handy, it's not difficult. You need to be able to handle some basic PVC plumbing...and thats about it.

What brand generator is recommended?

I second the Circupool brand, but if you have any other automation on your pool, or plan to have it, you may want to consider ones that have more options in that regard.

How long do the salt cells last for?

Cells are rated in hours@xx lbs Chlorine/day@100% - so for example, the RJ-45 is rated at 15000 hrs @ 2lbs/day. In your 15000 pool, 2lbs a day would be 16ppm of FC. If you typically use 2PPM/day, then you only need to run at 12.5% (1/8th), or 100% for 3hours a day (or 50% for 6 hours etc)....so your 'lifespan' is 15000 at 3hours a day, so 5000 days, or about 7 years...

What size system should I get? I've read that you should deliberately oversize it.

Oversizing gives you more headroom should you need to boost FC, plus the bigger cells dont cost proportionately more, so your cost-per-ppm goes down.
The cells themselves are generally very close in price - the RJ-30 cell is currently about $610, the RJ-45, $690, so for $80, you're getting an 'extra' 50% lifetime in the cell.
Also, you often see deals where you can upgrade to the bigger model for a token fee - like $10 to go from the RJ-30 to the 45, you get basically 50% more 'life' for $10.

How much money could I expect to save vs Chlorine?

Your mileage may vary...depending on what you pay for LC, and how much your current pool uses etc.
Assuming $5/gallon for 12.% (which is pretty cheap) - at 2ppm/day in your pool, that would be about $1.25/day
Assuming our SWG example above, your replacement cell cost over 7 years would be rougly $700 / 5000days = $0.14/day
So, somewhere around $1.10/day, $30-40/month, plus you don't have to lug bottles of chlorine around etc.
If you pay more for LC, then your savings will be more. If you need more than a gallon every 4 days, then probably you'll save more...
I cannot stress how nice it is not to have to lug 35lbs of chlorine jugs from the hardware store once a week....

Does the system produce CYA?

Nope. Salt is broken down by the cell into Chlorine and mystery stuff (others can explain the chemistry...I assume it's just magic) and then once it's done, turns back (mostly) into salt again. Its like a miracle !
No CYA is involved, although you do still need some in the pool (none is ADDED by the process unlike Dichlor/trichlor)

Is it a mostly hands-off process of maintaining chlorine levels?
I can be pretty bad about staying on top of adding chlorine too the pool/shocking the pool as I am quite forgetful.
I know you still need to stay on top of acid levels.

Hands off, no. Much less hands on ? Sure, once you have it dialed in, if you forget for a day or two, you're not going to have a green pool.

And Dang, Newdude beat me to it

 

[Newdude]

And Dang, Newdude beat me to it

You improved on my maths, forgetting a critical part of the equation. The replacemnet cells don't need a controller because it lasts for several cells. My replacement cell costs of 4X ROI were at the full system price. With only a $750 cell needed for rounds 2+ (with 8.1% local sales tax), it would produce near $0.11 per FC at today's prices. Dirt cheap and convenient as all get out to have chlorine produced in one's backyard by pushing a button.

 

[DavidArmenB]

You got amazing information above for all of your questions. I’m just here to add my experience and give my advice.

First off, my advice is to absolutely get a SWCG if you want to pay a lot less per pound of chlorine and if you want to do less maintenance in your pool. The only thing I do is add Muriatic Acid about once a month. Everything else, including the suction side vacuum that also brushes the floor and walls, is automated.

I have a custom made automation system I put together to give me total control over my entire pool system, including 4 valve actuators. However, because it isn’t an official automation system, I could only control/automate the power to the SWCG system but I could not control the SWCG output percentage. Because of this, I bought the Hayward Aquarite as I liked the idea of the stand alone control center that I could use to set output percentage and view diagnostic information and the fact that changing the cell would be cheaper because the brains are not inside the cell, the way it is with the Pentair system. The cell only houses the rare metal plates and the temperature sensor. I believe the aforementioned Circupool RJ-45 will give you the same stand alone features as the Aquarite. I say the RJ-45 because I also highly recommend you get the biggest cell you can, regardless of your pool size.

Another thing to add, do not rely on the flow switch (which you may need to plumb separately depending on which system you get, but others have it inside the cell) to control power to the cell. You need to completely power off the SWCG whenever you do not want it to produce chlorine. The flow switch can break in the closed position. If this happens and your pump is not running, the cell will continue to produce, and it will produce so much hydrogen gas in the pipes that the pipes explode.

My cell is the t-15, which is rated for up to 40,000 gallons and produces 1.47 pounds of chlorine per 24 hours at 100% (via Pool Math’s Effects of Adding section). This is 11ppm for my 16,500 gallon pool/spa.

With a CYA of 80ppm, and a year-round FC concentration of 10ppm, FC consumption peaks at around 4ppm per day in the peak of summer, and drops down as low as 0.2ppm per day in the winter.

My SWCG runs for 19 hours a day, so I change the output rate of my cell from about 45% in the peak of summer down to about 5% in the winter (before the cell shuts down when water temp drops <50f) sometime in December and stays dormant until March the next year. I would say I change the rate about 8-12 times between March and December, when I go from 5-10% in March, up to 45% by July/August, and then back down to 5% by December.

If I average out my output throughout the year, you can anecdotally say I run at ~18% throughout the entire year (365 days). 18% for 24 hours on the t-15 is 0.265lbs FC per day. For 19 hours, which is what I run, it is 0.2bs FC per day, which is 73lbs FC per year. The T-15 cell is advertised to produce 580lbs FC during its life. This should give me almost 8 years before the cell is fully depleted.

So, on the full picture, if we count only the cell, I pay $900 every 8 years to chlorinate my pool. That’s only $112.50 per year.

 

[SJPoe]

Another thing to add, do not rely on the flow switch (which you may need to plumb separately depending on which system you get, but others have it inside the cell) to control power to the cell. You need to completely power off the SWCG whenever you do not want it to produce chlorine. The flow switch can break in the closed position. If this happens and your pump is not running, the cell will continue to produce, and it will produce so much hydrogen gas in the pipes that the pipes explode.

Another option is to run 24/7 with the new Variable Speed pumps - My VSP pulls less than 150 watts at super low speed...too low to trigger the heater or SWG flow switches, but enough to stop any build up of gasses.
Also, you can wire the SWG power to be in line with the pump power (so if the pump isn't powered, the SWG isn't powered) if you power on/off your pump. With the variable speed/app controlled pumps, this may not be an option, as the pump is powered all the time, and its own control panel may control when it actually pumps water etc.

I have some automation that checks that the pump is drawing more than a trickle of power (i.e. its actively pumping water hard enough to trigger the SWG flow switch) or it turns the wifi-enabled outlet that the SWG is plugged into off. That is a 'safety' in addition to the flow-switch itself.

Of course, lets not even get started on how much the VSP saves me in electric cost over my old single-speed Hayward SuperPump

 

[DavidArmenB]

Another option is to run 24/7 with the new Variable Speed pumps - My VSP pulls less than 150 watts at super low speed...too low to trigger the heater or SWG flow switches, but enough to stop any build up of gasses.
Also, you can wire the SWG power to be in line with the pump power (so if the pump isn't powered, the SWG isn't powered) if you power on/off your pump. With the variable speed/app controlled pumps, this may not be an option, as the pump is powered all the time, and its own control panel may control when it actually pumps water etc.

I have some automation that checks that the pump is drawing more than a trickle of power (i.e. its actively pumping water hard enough to trigger the SWG flow switch) or it turns the wifi-enabled outlet that the SWG is plugged into off. That is a 'safety' in addition to the flow-switch itself.

Of course, lets not even get started on how much the VSP saves me in electric cost over my old single-speed Hayward SuperPump

24 hours is optimal and my pump also runs at 24 hours. However, my electricity costs 2.5x the normal rate from 4pm to 9pm so I turn off anything that isn’t strictly necessary inside those hours. My schedule also lowers my pump speed from 1250rpm (130W) to 800 rpm (50W) inside those hours.

 

[Newdude]

800 rpm (50W) inside those hours.

Lol. I can do 700 RPMs at 35W and still activate the SWG flow switch. Loves me a VS pump, I do. There comes a point where I don't try and save anymore because it's already peanuts.

 

[DavidArmenB]

Lol. I can do 700 RPMs at 35W and still activate the SWG flow switch. Loves me a VS pump, I do. There comes a point where I don't try and save anymore because it's already peanuts.

My flow switch still works at those RPMs, I just manually shut off the SWCG during those hours (together with many other things throughout the house) to save electricity.

 

[Rodex]

Stay away from the Circupool Edge-25 or anything with the same housing and thread design. It’s been a struggle trying to keep it from leaking at the couplers. The controller had many issues (and was cracked out-of-box) and the company wouldn’t replace it.

I like the idea of a SWCG but this particular one is frustrating.

 

[wireform]

All the the advice before me is excellent as long as the chemistry is at optimal or close to optimal using poolmath and the advice here on the forum. You don't want to have to clean the cell as that will shorten its life span. Many on this forum myself included don't have the need to clean the cell for several seasons in a row only because of good chemistry.

 

[apono]

How do you measure pH with CYA=80 and FC ~10? Is the standard test reliable with this FC level?
I will be installing CircuPool RJ-60 PLUS (bought it for $1,379 + tax).

 

[Newdude]

How do you measure pH with CYA=80 and FC ~10? Is the standard test reliable with this FC level?

I often find that 4, or even 3 drops of phenol red puts it back on the right color spectrum. The color is the important part, not the # of drops.

Or it still fluctuates and you can time the PH tests when the FC dips below 10.