Help w/ switch to SWG

[kllentini]

Hi everyone, I had started a similar thread about test kits but I guess I need some general help with my new switch to SWG from chlorine so I’m starting this thread. The new SWG pool is a vinyl liner with about 20,000 gallons, DE filter and Hayward TCell 940 w/ Hayward AquaRite 900.

New water got filled and I’ve been running the pump 24/7 past few days slowly adding salt and am also currently doing the sock method for CYA. And I got my 1766 kit last night so I tested this morning. So right now I’m at:

Salt - 3,300 (overshot a bit as manufacture recommended 3,200 but it’s still in OK range)

CYA - 25-30 and I’m still adding via sock method. What is my ultimate goal for CYA, 70?

FC - .5. (I added a little liquid chlorine to get some in the pool, but I have a question about this going forward)

pH is good

My main questions are on how do I work this SWG going forward. At this stage do I need to add liquid chlorine per the FC/CYA chart and let the SWG maintain or I thought the SWG generates chlorine? I’m not sure what percentage to put it on, and do I run chlorinater the entire time the pump is running? And then what, if anything should I test to make sure it’s running where it needs to be, FC? Thanks to anyone in advance who has input as I tackle this new learning curve.

 

[mknauss]

Raise your FC to target level for your CYA. Set the SWCG to generate 3 ppm FC per day and test each day to be sure the FC is at or above the target level. Adjust SWCG if necessary. Once CYA is at your goal level and your FC is stabilized, you can limit testing to every other day or so.

 

[B.lu]

Hi, I'm figuring out my SWG as well. This is my first summer with it. I am sure others will have suggestions but my understanding is that you need to add liquid chlorine initially (shoot for 3ppm) then the SWG to sustain/increase as needed. From my experience, the schedule takes some tweaking. I put my pump on from 7am to 6pm and have been setting the SWG at 45%-75%. Initially, 75% was producing to much so I dropped down to 35% and now am building up to find the optimal amount. Your pool with be different likely.

 

[AK-]

And then what, if anything should I test to make sure it’s running where it needs to be, FC?

Use PoolMath to calculate % and runtime

FC - .5. (I added a little liquid chlorine to get some in the pool, but I have a question about this going forward)

Always use LC to bring your FC to the level it needs to be. SWGs excel at maintaining FC, but are not that great getting there.

 

[B.lu]

Hi, I'm figuring out my SWG as well. This is my first summer with it. I am sure others will have suggestions but my understanding is that you need to add liquid chlorine initially (shoot for 3ppm) then the SWG to sustain/increase as needed. From my experience, the schedule takes some tweaking. I put my pump on from 7am to 6pm and have been setting the SWG at 45%-75%. Initially, 75% was producing to much so I dropped down to 35% and now am building up to find the optimal amount. Your pool with be different likely.

and I second what Mknass said about testing. I am doing daily or even twice a day (am/pm) to better understand when my setting adjustments are leading to

 

[bertschb]

...do I need to add liquid chlorine per the FC/CYA chart and let the SWG maintain

Yes

...and do I run chlorinater the entire time the pump is running?

Yes, this is what most people do.

And then what, if anything should I test to make sure it’s running where it needs to be, FC?

Yes. I would test FC daily until you get the SWCG adjusted where you want it.

 

[Oly]

Test your water just before your system starts up after being off, as this is the expected FC low point of the day. Some folks run 24/7 so this would not apply.

 

[kllentini]

Hey thanks for these responses. I remain confused as I’m working thru this. I’m pretty familiar with Pool Math and have used it the last several years before this year’s switch to the SWG. I’m not sure how I can use it to calculate % and run time. Mknauss you said to set the SWCG to generate 3 ppm per day - how is that done specifically? I don’t see any recommendation in my SWGC manual or I haven’t seen an article on this site that sort of spells out how to set it to reach that 3ppm target.

So hypothetically let’s say I get my CYA at 60 and my FC to 3 via liquid chlorine. If I tweak my run time and % to have the SWCG generate 3ppm per day - then what should my FC test result be when I test in order to confirm the SWGC is generating about 3ppm per day? B.Lu you said you’ve been on an 11 hour run cycle and trying % between 35-75. What results were you getting that told you 75% was too much and what result are you looking for to know you’re on target?

Thanks again in advance for any advice and input.

 

[B.lu]

Hey thanks for these responses. I remain confused as I’m working thru this. I’m pretty familiar with Pool Math and have used it the last several years before this year’s switch to the SWG. I’m not sure how I can use it to calculate % and run time. Mknauss you said to set the SWCG to generate 3 ppm per day - how is that done specifically? I don’t see any recommendation in my SWGC manual or I haven’t seen an article on this site that sort of spells out how to set it to reach that 3ppm target.

So hypothetically let’s say I get my CYA at 60 and my FC to 3 via liquid chlorine. If I tweak my run time and % to have the SWCG generate 3ppm per day - then what should my FC test result be when I test in order to confirm the SWGC is generating about 3ppm per day? B.Lu you said you’ve been on an 11 hour run cycle and trying % between 35-75. What results were you getting that told you 75% was too much and what result are you looking for to know you’re on target?

Thanks again in advance for any advice and input.

When I had the SWG at 75% my FC was 8, which is too high based on my CYA. My CYA is low at 20 and I’m working on raising it now. At FC of 8 the CYA chart on this site says I should have 50 CYA. Where I live the water is still chilly, at low 70s so we aren’t swimming much (my kids jump in a bit). Im guessing in the summer I’ll need a higher setting with more chlorine production due to heat and increased bather load

 

[mknauss]

Mknauss you said to set the SWCG to generate 3 ppm per day - how is that done specifically?

Use Poolmath. The Effects of Adding Chemicals.

Add your SWCG to your signature. We can help you better if we know what equipment you have.

 

[mknauss]

CYA at 60 and my FC to 3 via liquid chlorine.

Use the Target level of FC for your CYA as your minimum. See FC/CYA Levels

 

[Rancho Cost-a-Lotta]

Mknauss you said to set the SWCG to generate 3 ppm per day - how is that done specifically?

Here's another way to figure out how to adjust SWG output.

In Pool Math, click on the FC tab. Set Target level 3 ppm above Current level.

Scroll down and click the search/magnifying glass icon. Select your SWG make/model or enter the 24 hour output (lbs. per/day) manually.

Select SWG% or SWG hours and result will show below. It should look like this...

 

[kllentini]

Thank you very much, this was the aha moment I guess I was searching for. I didn’t realize that SWG was a sanitizer option in Pool Math and that picture cleared it up. But I have a follow up - what is the value represented under “24 hour SWG Output”. You used a 2 in your example but I’m not sure what that represents. Thanks again.

 

[AK-]

Thank you very much, this was the aha moment I guess I was searching for. I didn’t realize that SWG was a sanitizer option in Pool Math and that picture cleared it up. But I have a follow up - what is the value represented under “24 hour SWG Output”. You used a 2 in your example but I’m not sure what that represents. Thanks again.

That is the rated output of you SWG Cell. You can find it on your SWG's manual. For most common SWGs you can click on the blue magnifying glass and search for it.

 

[Rancho Cost-a-Lotta]

It represents 2 lbs of chlorine gas per 24 hours. This assumes the unit is run 24/7, at 100% output. As Marty suggested, you can also use the "Effects of Adding" tab. Select "Chlorine Gas" in the "Chemical Additions" box.

 

[Rancho Cost-a-Lotta]

That is the rated output of you SWG Cell. You can find it on your SWG's manual. For most common SWGs you can click on the blue magnifying glass and search for it.

Yes, I'm probably confusing things. My unit puts out 2 lb. Yours may be different.

 

[MITBeta]

But I have a follow up - what is the value represented under “24 hour SWG Output”.

Scroll down and click the search/magnifying glass icon. Select your SWG make/model

 

[kllentini]

Guys thank you very much. I switched from chlorine to SWG this year and I was stuck on the old way of using the Pool Math app. My wife tells me I’m an idiot and like in many cases, she’s right. This forum is such a great resource for pool owners, I learned about it from a friend who owns a pool and I always point other pool owners I know to it now. Thanks again for all the help.

 

[mknauss]

This forum is such a great resource for pool owners,

We are glad you have found our information helpful. Please, if you can, consider making a donation to TFP. We are staffed by volunteers and are registered as an IRS 501 (c) (3) charity and donations are what keeps the forum operating without advertisements.

Support TFP!

 

[wireform]

Guys thank you very much. I switched from chlorine to SWG this year and I was stuck on the old way of using the Pool Math app. My wife tells me I’m an idiot and like in many cases, she’s right. This forum is such a great resource for pool owners, I learned about it from a friend who owns a pool and I always point other pool owners I know to it now. Thanks again for all the help.

We need you to do this now Become a TFP Supporter
Marty jumped me at it