New to SWG and my pool just turned cloudy - I have numbers

[caliskier]

Hi All,

My pool just turned cloudy today, we had a large rain storm 4 days before, and I noticed I needed to backwash. I am new to SWG but my SWG is not new. Have been using liquid chlorine for 5 years. I installed it late last year and opened the pool 5 weeks ago. Its been cool, opened at 61 degrees, now its 71. I have been running 6 hours a day at 60% right before it turns on my chlorine level is around 2.0 I ran the SWG all day for 10 hours at 100%, and turned on super chlorinate after 10 hours (why is a long story). SWG in my sig, but its a Hayward for 40,000 gallon pool and this pool is 21,600 gallons

• Chlorine levels at 7 hours were 1.5ppm combined chlorine unknown, at 8 hours they were 2ppm and 0 combined chlorine, at 10 hours it was 3.5ppm I assume CC is still 0
• Chlorine = 3.5
• CC = 0
• CH = 350
• TA =110-120
• PH = 7.7
• CYA = 55-60
• Water Temp 71 degrees
• Salt level per the machine is 2900ppm

So questions:

1. Does it take a while to ramp up? I assume when I started it was at 0 and took 7 hours to get to 1.5?
2. What is the best way to get it clear now
3. What should I do different after it clears?
4. Is any of this an indication of a bad cell?

 

[Jimrahbe]

Cal,

I am sure you have seen the saltwater section of this chart.. but want to make sure... FC/CYA Levels

I always suggest that SWCG owners run their FC at their "Target" or higher.. I never recommend trying to keep your FC between your minimum and your target...

This is especially true if you are only running your pump for a short time.. If you only run your pump for 6 hours a day, then that leaves 18 hours without any additional chlorine being added.. One reason for a low FC level being allowed when using a SWCG is that you are generally add a little chlorine for a long period of time.. The less you run the pump, then the higher your target needs to be..

The FC still needs to be close to your Target just before the SWCG fires up after being off for 18 hours. Not doing this gives you zero capacity to recover from heavy rains storms, large swimmer loads, or anything else that can cause your FC to quickly drop.

I suggest that you test, just before your SWCG is scheduled to come on, and make sure that you are not anywhere near your minimum FC.

There is just no downside to running your FC at your target or higher.. While there is a huge downside with running your FC too low.

Thanks,

Jim R.

 

[Jimrahbe]

Cal,

Also.. Your cell will generate 7.6 ppm of FC in your pool when run at 100% output and 24/7... That is .31ppm per hour.

If you run the SWCG at 60% that is only .19ppm per hour.. For 6 hours that is only 1.14 ppm of FC..

Thanks,

Jim R.

 

[DLip]

If you’re starting w/ zero (or near zero) chlorine it’s easiest to reach your target using liquid chlorine. Once target reached turn on SWG and adjust output accordingly based on testing.
You can get there w just the SWG but it takes a while and you’ll run into issues if your levels are too low for too long

 

[caliskier]

If you’re starting w/ zero (or near zero) chlorine it’s easiest to reach your target using liquid chlorine. Once target reached turn on SWG and adjust output accordingly based on testing.
You can get there w just the SWG but it takes a while and you’ll run into issues if your levels are too low for too long

Cal,

Also.. Your cell will generate 7.6 ppm of FC in your pool when run at 100% output and 24/7... That is .31ppm per hour.

If you run the SWCG at 60% that is only .19ppm per hour.. For 6 hours that is only 1.14 ppm of FC..

Thanks,

Jim R.

@DLip, Thanks for the help, I do have some liquid chlorine, I assume I need to bring to shock level and use the generator to hold it there?
@Jim, first, nice picture, is that you? Second, thanks for both posts, very good information and I knew I was too low, knew it... just was thinking it would be ok if I just keep raising the output. The calculation is really helpful as well is that for my size pool? 40k vs 20k would make 2x difference. Like you said, need to have it above target when it starts and hold it there.

 

[DLip]

You bet. If you’re going to SLAM the TFP article recommends using liquid to reach and maintain SLAM FC level (and turn the SWG off - tough to maintain those levels w SWG)
Not sure you need to SLAM though with zero CC. I would bring FC to your normal target level w/ liquid, turn on swg, then monitor your FC/CC levels and cloudiness for a couple days.
It takes a bit of trial and error to dial in the SWG for stable FC but after you get it dialed in it’s smooth sailing.

 

[caliskier]

You bet. If you’re going to SLAM the TFP article recommends using liquid to reach and maintain SLAM FC level (and turn the SWG off - tough to maintain those levels w SWG)
Not sure you need to SLAM though with zero CC. I would bring FC to your normal target level w/ liquid, turn on swg, then monitor your FC/CC levels and cloudiness for a couple days.
It takes a bit of trial and error to dial in the SWG for stable FC but after you get it dialed in it’s smooth sailing.

Thats a good thought, If I don't have to slam with 0 CC I would rather not.

 

[Jimrahbe]

first, nice picture, is that you? Second, thanks for both posts, very good information and I knew I was too low, knew it... just was thinking it would be ok if I just keep raising the output. The calculation is really helpful as well is that for my size pool?

Cal,

The avatar is a selfie of me about a billion years ago, before selfies were even a thing.. I'll send you a PM..

The FC numbers came from Pool Math and were calculated for your pool size and your T-15 SWCG..

Thanks,

Jim R.

 

[caliskier]

Cal,

The avatar is a selfie of me about a billion years ago, before selfies were even a thing.. I'll send you a PM..

The FC numbers came from Pool Math and were calculated for your pool size and your T-15 SWCG..

Thanks,

Jim R.

Thanks Jim... Ok, just now I checked, been running all night 100% at super chlorinate... 3 PPM chlorine, no CC. Do I have a problem?

 

[Jimrahbe]

Cal,

If running at 100% then the cell should generate .31 ppm per hour.. I am not sure what "all night" means..

I suggest that you run a standard OLCT with the cell off... Overnight Chlorine Loss Test I'd use liquid chlorine to get your FC up to 5 ppm, or higher, and then run the OCLT. If you can't pass the OCLT then nothing else matters, you have algae..

If you pass the OCLT with no loss, or very little loss, then run another OCLT.. but this time with the Cell on at 100%.. You should then see the FC increase overnight and it should be "about" .31 ppm per hour of run time at night...

Thanks,

Jim R.

 

[mguzzy]

So questions:

1. Does it take a while to ramp up? I assume when I started it was at 0 and took 7 hours to get to 1.5?
2. What is the best way to get it clear now
3. What should I do different after it clears?
4. Is any of this an indication of a bad cell?

1) yes it takes awhile to ramp up.. as Jim mentioned it will only produce .31ppm/hr so that is why its recommended to bring it up to your target with liquid chlorine and let the SWG take over.
2) If its just cloudy.. raise your FC with liquid chlorine and filtration should do the reset.
3) Get an idea for how much FC you use per day.. and keep in mind that number will go up as you progress through the summer and back down as you approach fall just from the changes of the sun. Add on to that bather load, etc. Then you adjust your runtime and output to match that load. once you get it figured out it will just be a tweak of the knob once a week as you go through the summer.
4) Probably not.

 

[caliskier]

Cal,

If running at 100% then the cell should generate .31 ppm per hour.. I am not sure what "all night" means..

I suggest that you run a standard OLCT with the cell off... Overnight Chlorine Loss Test I'd use liquid chlorine to get your FC up to 5 ppm, or higher, and then run the OCLT. If you can't pass the OCLT then nothing else matters, you have algae..

If you pass the OCLT with no loss, or very little loss, then run another OCLT.. but this time with the Cell on at 100%.. You should then see the FC increase overnight and it should be "about" .31 ppm per hour of run time at night...

Thanks,

Jim R.

all night means I have not turned it off. I will do the liquid chlorine and see what I get

1) yes it takes awhile to ramp up.. as Jim mentioned it will only produce .31ppm/hr so that is why its recommended to bring it up to your target with liquid chlorine and let the SWG take over.
2) If its just cloudy.. raise your FC with liquid chlorine and filtration should do the reset.
3) Get an idea for how much FC you use per day.. and keep in mind that number will go up as you progress through the summer and back down as you approach fall just from the changes of the sun. Add on to that bather load, etc. Then you adjust your runtime and output to match that load. once you get it figured out it will just be a tweak of the knob once a week as you go through the summer.
4) Probably not.

Thanks for the info, and 3 and especially 4

 

[caliskier]

Ok,

I raised it to 24 PPM based on the CYA level of 60. I did this last night at 8:30 and then my pump went off at 9:00 because I forgot to set it to manual. I woke up at 5:30 and turned it back on 100% and super chlorinate. It is now 20 PPM, much clearer but there is foam on the top of the pool.

Question I have is... I ran 12 hours, at .31 ppm per hour that should be 4 PPM total. Starting at 24PPM that would be 28 right? But I am at 20 now. Could have had some issues with CC, and could have had a little loss to sunlight, but 8PPM seams like a lot.

 

[DLip]

Yeah sounds like algae, you’ll need to slam until the overnight loss is 1.0 or less.
I would just turn off the SWG and slam w liquid so you can keep the pump running and not throw off the overnight loss reading.

 

[caliskier]

Yeah sounds like algae, you’ll need to slam until the overnight loss is 1.0 or less.
I would just turn off the SWG and slam w liquid so you can keep the pump running and not throw off the overnight loss reading.

Thanks for that, not a problem with the cell?

 

[DLip]

I doubt it, but impossible to be sure until the algae problem is gone. As long as you’re losing chlorine due to algae, it’s impossible to know how much the SWG is producing. Once you take that loss out of the equation (by passing OCLT) you’ll be able to measure SWG output more accurately.

 

[caliskier]

Thanks that makes sense. There is foam on top of the pool, covered.