1. ## SWG Chlorine Calculation

Can someone check my math and see if I'm doing this correctly?

I have a pentair IC 40 which claims to produce 635g of 'pure chlorine' per 24 h period (I assume this is at 100%).
so I run my pump 12 hours (3 hours, 4 times per day due to time of use pricing). I feel that gives sufficient turnover and skimming action..

I've read I need to replace about 2.5 ppm daily of chlorine.

SO... I *think* this is correct:
according to pool math, 635g of Chlorine Gas (I think) is a rise of 6.4
in 12 hours that's a rise of 3.2

running the unit at 80% should give me 5.12ppm in 24 hours, so at 12 hours run time it should be just over 2.5

Am I making sense?

Joey

2. ## Re: SWG Chlorine Calculation

Yes, but there are other factors. Amount of sunlight, CYA level and bather load are factors. Run it at 100% with pump at 12 hours. Measure your FC level before, then the next day or two. If chlorine is going up, you can either turn down the pump run time or the SWCG. (I'd recommend turning down the pump run time. It uses more energy.)

3. ## Re: SWG Chlorine Calculation

You should not need anywhere close to 2.5 ppm per day. If your CYA is at 80 ppm (4 ppm FC target), extinction should not be more than 25% so at most you should only need 1 ppm per day.

Also, I hope you are not running 12 hours per day for turnover because that is pretty much a meaningless metric. Please read this: Pool School - Determine Pump Run Time

5 hours of run time per day should meet both the SWG and skimming requirements.

4. ## Re: SWG Chlorine Calculation

Originally Posted by mas985

Also, I hope you are not running 12 hours per day for turnover because that is pretty much a meaningless metric.

5 hours of run time per day should meet both the SWG and skimming requirements.
Not for turnover per se, more that if I run it less than that, there's SO MANY leaves in the pool. There's a large tree over the pool which I like, and we have a very small skimmer compared to the size of the pool in my opinion.

Sent from a tiny keyboard.

5. ## Re: SWG Chlorine Calculation

Get a solar skimmer

6. ## Re: SWG Chlorine Calculation

Originally Posted by Yaniv
Get a solar skimmer
Having never heard of this a quick google search turned up the solar breeze, which while seeming totally awesome and geeky at the same time, has a pretty hefty price tag. Not sure how long I'd have to not run my pump to save money on the \$750 price tag.

Sent from a tiny keyboard.

7. ## Re: SWG Chlorine Calculation

This chart should help you with figuring out how long to run the SWG.

The factor here is knowing the FC demand for a 24 hour period. You can determine this by increasing FC to higher than needed, test, wait 24 hours and then test again. The difference is the FC loss. The more days that you do that and average them, the more accurate it would be.

See the SWG Calculator link in my signature for the process to tweak the run-time / % output until the FC is staying fairly consistent day to day.

8. ## Re: SWG Chlorine Calculation

Originally Posted by mgmoore7
This chart should help you with figuring out how long to run the SWG.

See the SWG Calculator link in my signature for the process to tweak the run-time / % output until the FC is staying fairly consistent day to day.
This. Is. Excellent.

Originally Posted by mgmoore7
You can determine this by increasing FC to higher than needed, test, wait 24 hours and then test again. The difference is the FC loss. The more days that you do that and average them, the more accurate it would be.
I am mid SLAM right now, so I could just check it every day as it drifts down to normal (with the swg off). I suspect that will take several days. Would that work the same, or is it different at such a high level. My shock level is 24 right now.

Sent from a tiny keyboard.

9. ## Re: SWG Chlorine Calculation

Originally Posted by BestJoeyEver
This. Is. Excellent.

I am mid SLAM right now, so I could just check it every day as it drifts down to normal (with the swg off). I suspect that will take several days. Would that work the same, or is it different at such a high level. My shock level is 24 right now.

Sent from a tiny keyboard.
Yes, i did the same thing , especially when it gets done to a lower level.

10. ## Re: SWG Chlorine Calculation

Originally Posted by mgmoore7
See the SWG Calculator link in my signature
This is a great tool, I sent you a PM about it.

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