I've been using bleach since I've had my pool for the past 3 summers and haven't had any problems. I'm considering installing a SWG to automate the process a little, of adding chlorine. During the summer I will at times put in 1 jug (121 oz) daily, sometimes a little more, to keep my FC levels up, I'm in full sun nearly all day. The pool is 24-25000 gal and I'm looking at the Pentair IC40. Looking at a comparison chart I found on discountsaltpools.com it says that this unit will produce 1.4 lbs/day of chlorine, I assume if running at 100%. My questions are: How many lbs of chlorine is in a jug of bleach, will this SWG be able to keep up with my demand without having to run 100% all of the time and how much supplementing will I have to do with bleach, should I be looking at a different unit and am I looking at this right or am I off my rocker?? Also, am I wrong in thinking that I can go away for a week in the summer and not come back to a pool severely lacking in FC or needing to SLAM it? Thanks.
SWG vs Bleach
- Thread starter Wrobert
- Start date
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You FC usage from bleach is ~3.3ppm/day. At full output an IC40 will add ~6.9ppm FC per day. You should probably consider an IC60 instead.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Yes. I've gone on 10 day vacations with my SWG.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
- Jun 12, 2011
- 3,761
- Pool Size
- 19500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
By way of comparison, I live in very sunny Tucson (300+ very sunny days a year). I have a pool that is right about 19k gallons, and am using a Hayward AquaRite AQR-15 (40k rated) and generally have it set In the 35-50% range. It is rare that I set it above 50% and even more rare that I use any bleach to supplement. I have had it for over 10 years and my first cell lasted 7+ years and cost $400 to replace. That makes my chlorine cost about $57 per year ($400/7=$57).
I have been very happy with the Hayward unit and have left on vacations for up to two weeks at a time with no problems. In the 10+ years, I have never had any algae problems at all.
I have been very happy with the Hayward unit and have left on vacations for up to two weeks at a time with no problems. In the 10+ years, I have never had any algae problems at all.
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You'll also need to figure that you'll be running your pump longer (not sure what your pump run times are now). That's the one thing people often overlook with SWGs - they only produce chlorine when the pump is running. I see you have a single-speed pump. Unfortunately that's a very costly way to run an SWG pool. If you plan to install an SWG, you might want to consider switching to a 2-speed pump (where the low speed is capable of running the SWG) or to a variable speed pump. When you have a VSP, you can very accurately dial-in the minimum RPMs you need to run the SWG and thus optimize your electricity usage.
- Jun 12, 2011
- 3,761
- Pool Size
- 19500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pureline Crystal Pure 60,000
True, I have a VS pump and should have clarified that the 35-50% was based on the SWG running about 8 hrs. per day.
+1 to going on vaca for 1-2 weeks with SWG. No problem. I use bleach to raise my FC up to SLAM level just for extra insurance. I also lower my PH to 7.2 and it's all good.
What is your CYA level currently? That's a big factor in FC usage. In the 2 summers we have had this house, the first was at 80ppm CYA, and we dropped 1-2ppm FC/day depending on temperature and how much the cover was on. The second summer was at 30-40ppm CYA, and I needed to replace 3-4ppm FC/day. So you may be able to factor a reduction in FC usage if you're at a level lower than the typical 80ppm SWCG recommendation here.
Thanks for all of the input. My CYA is usually around 40-50 so it may help to raise that, and if I'm not mistaken I'll have to have my FC higher to account for the CYA also, to have remain effective? As far as the pump, that's one of the things that I was looking at too. I figured I might have to get one that is more than one speed to make this all work right without having to keep it running full all of the time. One concern I have is the pH. Where should that be for the SWG? Mine has a tendency to drive up and I'm having to put MA in it all of the time to keep it down; since my pool is only in the 3rd summer this year I'm hoping it starts to stay down easier. I've been told newer plaster pools drive pH up. I don't remember what my TA is, I think usually around 80.
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Yes, with higher CYA you need to maintain a higher target FC level. However, the higher CYA should give you better protection from UV photolysis of the chlorine and thus a lower FC loss rate (or not any worse than you already experience).
A 2-speed pump would be a significant improvement in savings. You must ensure the pump is large enough to give you the correct flow rates when run on LOW.
Your pH is rising because your TA is too high. Try lowering your TA to find the point at which your pH is stable or the acid addition frequency is as low as you can get it. You shouldn't go any lower in TA than 50ppm unless you have a secondary pH buffer in the water from 50ppm borates.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
Great.... Playing with the TA was my next thing to do for the pH, I guess I'll have to be a little more aggressive with that this year. As far as the pump: I assume that a VS would be the best and 2 speed adequate? Probably comes down to cost, but if I'm going to buy one will I be disappointed if get the 2 speed even thought it will most likely perform fine?
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Many folks will balk at the up-front cost of a VSP (~$1,000). Unless your electric utility rates are really high, a VSP will not pay for itself in any meaningful length of tine. By contrast, 2-speed pumps are a lot cheaper and can have a reasonable ROI if your utility rates are high. On the other hand, if cost is not an issue, a VSP is much easier to plug & play because it does not require any additional electrical rewiring that a 2-speed does AND you get to optimize your pump speed for whatever you need. As well, most VSPs have on-board controllers that allow you to set schedules and have push-button single speed options (like a high speed quick button press for vacuuming). One thing with a VSP though is you should really protect it with a surge protector at the electrical panel where it is powered from as VSPs tend to get fried by lightening strikes.
So it really depends on what you're willing to spend and how fancy you'd like to get.
Two things I just thought of and was curious about: When swimming in a SWG pool does a person notice the salt water when opening their eyes underwater? I, as well as my 5 y/o, do it all of the time in the pool without problem now. Also, the cell produces chlorine when the pump is running, I assume that the pump can be running for just filtering without the cell producing chlorine. Correct?
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Salinity for an SWG is only 3600ppm. That's about 10X less than seawater. I bet with your bleach and acid use that your pool water probably already has a chloride concentration near 2000ppm (unless you get a lot of rain water dilution and exchange). So you should not experience any issues with opening your eye. Most people can barely taste the salt.
Yes, the pump can certainly run and not have the SWG generating chlorine. It all depends on how you have things wired and programmed.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
Yes, the pump can certainly run and not have the SWG generating chlorine. It all depends on how you have things wired and programmed.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
- Jan 4, 2016
- 5,288
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
From what I've read and experienced, the salt in the water makes the water easier on the eyes, being closer to the salt in tears.
We run our pump and chlorinator during daylight and while swimming. Our saltwater chlorinator puts out less than 1/60th of an ounce (<1/2 a gram) per minute, diluted in 30 gallons (110 litres) of water per minute. That adds about 4 ppm FC to the return pipe, plus 5 ppm FC in the pool. So with the SWG running, the water coming out of the pool returns is around 9 ppm FC and well within safe swimming limits.
If you've ever had itchy or red eyes from swimming elsewhere, try blinking instead of rubbing your eyes when you come up. It's a dramatic difference (and works the same in the shower). I didn't believe it when I read it and had always blamed soap, shampoo, chlorine or mystery chemicals. It took me a week or so to learn blinking, which I did by putting my glasses on right away. It was definitely the eye rubbing for me. I learned it from a swimming instructor who teaches her kids to "Blink, Blink, Blink." Sorry for going off-track, but we play a lot of games that involve swimming down to the bottom and fetching, so it was a handy thing to learn!!
We run our pump and chlorinator during daylight and while swimming. Our saltwater chlorinator puts out less than 1/60th of an ounce (<1/2 a gram) per minute, diluted in 30 gallons (110 litres) of water per minute. That adds about 4 ppm FC to the return pipe, plus 5 ppm FC in the pool. So with the SWG running, the water coming out of the pool returns is around 9 ppm FC and well within safe swimming limits.
If you've ever had itchy or red eyes from swimming elsewhere, try blinking instead of rubbing your eyes when you come up. It's a dramatic difference (and works the same in the shower). I didn't believe it when I read it and had always blamed soap, shampoo, chlorine or mystery chemicals. It took me a week or so to learn blinking, which I did by putting my glasses on right away. It was definitely the eye rubbing for me. I learned it from a swimming instructor who teaches her kids to "Blink, Blink, Blink." Sorry for going off-track, but we play a lot of games that involve swimming down to the bottom and fetching, so it was a handy thing to learn!!
All of this input is great, thanks. Back to one of my original questions: 1 jug of bleach = how many pounds of chlorine? Most of the specs on the generators have pounds/day and I wanted to know how many jugs that would be in comparison.
We tend to also have a high chlorine demand because of not putting our cover on (it's a pain in the butt) and being in direct sun most of the day. Hopefully raising the CYA this year will help even if we don't get a SWG this season. I'm just worried that we'll get a generator and it won't be able to keep up with the demand and I'll still have to add bleach all of the time. Probably not as much but the whole thought is not having to deal with that, except for SLAM and the occasional big pool party.
I'm sure there's a more direct formula available, but I used the "Effect of adding chemicals" tool at the bottom of http://www.troublefreepool.com/calc.html. Plugging in 22.4 oz (1.4 lbs) of Chlorine Gas for my 22000 gal pool will raise FC by 7.6. By comparison, 128oz of 8.25% bleach raises FC by 3.9 (check the jug size and percentage that you're comparing against). You can plug in your own size/etc numbers there, but effectively the IC40 can generate the equivalent of ~2 jugs a day of common bleach -- if it were run 24hr/day.
If you run your pump 8 hours a day, it's equivalent to 2/3 of a jug, or raising the FC by 2.5 for my pool. From my experience, at CYA 80 that would be sufficient for the peak summer days even when the cover is off. I have a VS pump, so increasing run time to 10 hours or more if needed for a few peak weeks wouldn't be that bad, though an IC60 would provide more headroom.
I'm debating SWCG vs a stenner pump myself, so keep coming back to these calculations (I have other considerations like old copper pipes weighing into the tradeoff).
One other factor that may or may not have any effect is that the SWG does not simply go ON and OFF (OK, technically it does) like the way you are adding bleach now. You dump a bottle in and 24 hours you dump another bottle in etc. The SWG creates chlorine the entire time it is running. One addition a day vs. thousands of tiny additions.
I wonder if a very consistent level of chlorine is better that a large amount that drops continuously over the day? Chem Geek, any ideas?
I wonder if a very consistent level of chlorine is better that a large amount that drops continuously over the day? Chem Geek, any ideas?
Based on the size of my pool, 17 ounces of 8.25% bleach raises my FC by 1ppm.
You just need to figure out the math based on your pool size (and liquid chlorine strength) at the bottom of Pool Math.
You just need to figure out the math based on your pool size (and liquid chlorine strength) at the bottom of Pool Math.