Are the SWCG even worth the cost anymore?

[mgarf33]

When I first installed the SWCG the math worked out to be a cheaper alternative to chlorine tablets. With the significant cost increase of the salt cells, it would almost seem the chlorine tablets would be less expensive. I'm looking at 26k gallons, and roughly $100 for 10 weeks of tablet chlorination vs. $150 per season cost for best case scenario on a 9 year life of a SWCG cell replacement. Everyone says, "oh, but the silky feeling of the salt pool". Uh, just add salt to your pool or leave the existing salt in your pool if you switch.

 

[PoolStored]

Does in my case...1.8yr payback...already paid for itself...this doesn't include gas cost and my time.

 

[JJ_Tex]

If you are comparing tablets, make sure you have accurate prices as those have also gone up along with seemingly everything else pool related (and not pool related too).

Also keep in mind that if you just use pucks, you will have to drain and refill every few years to keep the CYA from building up, so add that cost into the equation.

Without doing the math, I would believe the numbers would be similar but the convenience factor of the SWCG trumps any minor cost savings. I also like being able to whip out my phone and "add more chlorine" from anywhere in the world.

 

[duraleigh]

but the convenience factor of the SWCG trumps any minor costs savings

+1 on that!

 

[mknauss]

You must have a very economic source of trichlor.

For a 3 ppm FC loss per day, you need to add 20 ounces of trichlor per day to your pool volume. For 100 days, that is 2000 ounces, or 125 pounds.

If you can purchase 125 pounds of trichlor tablets for $150, do it.

 

[markayash]

You did have me curious so I checked. Amazon has 100 pds for $479

 

[mgarf33]

Does in my case...1.8yr payback...already paid for itself...this doesn't include gas cost and my time.

View attachment 505658

Thank you for the actual data, this helps. I'm just going off the videos online stating 5k gallons per 3"puck for 7 days. So, with a 25k gal pool that's 5 pucks per week? 50 pucks in a 25lb bucket would be 10 weeks for ~$100. While I have a 400Mbtuh gas heater, we typically don't use the pool in April or Oct. In reality we are 20 weeks max. From my online guesstimate I was looking at $200 per year in tablets, so the cost differential is on par with a best case scenario payback on the SWCG.

 

[mgarf33]

If you are comparing tablets, make sure you have accurate prices as those have also gone up along with seemingly everything else pool related (and not pool related too).

Also keep in mind that if you just use pucks, you will have to drain and refill every few years to keep the CYA from building up, so add that cost into the equation.

Without doing the math, I would believe the numbers would be similar but the convenience factor of the SWCG trumps any minor cost savings. I also like being able to whip out my phone and "add more chlorine" from anywhere in the world.

Good point about the CYA. I don't ever have a problem with CYA using the SWCG.

 

[PoolStored]

You did have me curious so I checked. Amazon has 100 pds for $479

Reworked with @markayash posted cost for pucks. That's a lot of draining during the year given the amount of CYA it adds (I reduced total CYA added by a 10ppm/month degradation)

 

[mgarf33]

You must have a very economic source of trichlor.

For a 3 ppm FC loss per day, you need to add 20 ounces of trichlor per day to your pool volume. For 100 days, that is 2000 ounces, or 125 pounds.

If you can purchase 125 pounds of trichlor tablets for $150, do it.

That seems like an awful lot. Each puck is 8oz, so you're saying I would go through 2.5 - 3" pucks per day, or 5 pucks every 2 days? That's 14 pucks per week! Most online sources suggest 4-5 3" pucks per week with a 25k gal water volume.

 

[PoolStored]

That seems like an awful lot. Each puck is 8oz, so you're saying I would go through 2.5 - 3" pucks per day, or 5 pucks every 2 days?

It depends on many factors. Is your pool shaded? Do you have a cover? Where are you located? What size and depth is your pool? How often do you have swimmers? FC demand for each pool is different.

In my pool, 1 puck adds 1.9FC and 1.1CYA. My demand is as listed in my two spreadsheets. Your demand will be your demand.

I can see FC usage spike to 5.5/day when I have sun, the cover is off and I have swimmers.

 

[jgofnj]

I am on just my second year. 1000% totally worth it without a doubt. I literally don't need to to anything to maintain my pool anymore, in fact, it's kind of boring now. Of course I keep my other levels in check, but once stable, I rarely ever have to make any adjustments. Best thing I ever did to my pool.

 

[mgarf33]

Reworked with @markayash posted cost for pucks. That's a lot of draining during the year given the amount of CYA it adds (I reduced total CYA added by a 10ppm/month degradation)

View attachment 505678

So, according to your spreadsheet, I would be at 222.50/year with a tablet use on a 25k pool and omitting April & October. This sounds about right.

 

[PoolStored]

Updated the second chart, had the price wrong. Payback is 2.5 years vs pucks (in my pool).

 

[mgarf33]

It depends on many factors. Is your pool shaded? Do you have a cover? Where are you located? What size and depth is your pool? How often do you have swimmers? FC demand for each pool is different.

In my pool, 1 puck adds 1.9FC and 1.1CYA. My demand is as listed in my two spreadsheets. Your demand will be your demand.

I can see FC usage spike to 5.5/day when I have sun, the cover is off and I have swimmers.

I haven't done the math on my pool, but most years with the properly operating T-15 cell it was set at around 15%-18% duty cycle and maintained properly chlorine level between 1.5-3ppm.

 

[PoolStored]

So, according to your spreadsheet, I would be at 222.50/year with a tablet use on a 25k pool and omitting April & October.

Your pool...Assuming that this FC demand is accurate for your pool.

 

[mknauss]

I haven't done the math on my pool, but most years with the properly operating T-15 cell it was set at around 15%-18% duty cycle and maintained properly chlorine level between 1.5-3ppm.

You have a magic pool. Or it is indoors or covered nearly 100% of the daylight hours. Only uses 1.2 ppm FC per day. That is with pump running 24 hours at 18% generation.

 

[mgarf33]

You have a magic pool. Or it is indoors or covered nearly 100% of the daylight hours. Only uses 1.2 ppm FC per day. That is with pump running 24 hours at 18% generation.

I guess so, but that's what it was kept at. I found setting at 20% or greater would cause >3ppm. Yes, the pump runs 24/7.

 

[mknauss]

Your target level FC is based on CYA. And 3 ppm is very low.

 

[proavia]

Keeping your FC level at 1.5 - 3 ppm is flirting with an algae bloom.
What is your CYA level?

Post a full set of current test results from one of the recommended test kits.
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