SLAM complete - What should expect from my SWG

[sendsley]

Thanks to TFP I seem to have successfully killed whatever was lingering in my water. It is now crystal clear, very little CC and almost zero OCLT. So for the first time in just over 2 season I have clean water (fought a battle all last season with chlorine levels - now I understand why and believe it's solved) and I'm not sure what I should expect from my SWG.

I run my pump/filter 24/7 and run the SWG 24/7. Should I see an increase in FC overnight with the SWG running or should it just be maintaining FC levels overnight and throughout the day?

Thanks!

 

[zimm]

I would think you should be able to generate more than enough chlorine with a 20,000 sized cell on a 11,000 gallon pool. Especially at 100% with the pump running 24/7. How old is the cell? When't the last time you looked at the plates to see if they need cleaning? What's your salt level?

I have a 27,000 sized cell on 17,000 gallons, and I'm running 30% duty cycle 8 hours a day and have plenty of FC.

 

[sendsley]

Assuming it was new when the pool people installed it (and that might be assuming too much) it would be 2.5 years old. I do clean it regularly, plates themselves look fine, some calcium build up on the brackets holding the plates that I've gotten as much off as possible. Salt is at least 3200, probably a bit higher since according to Pool Math all the bleach I added over 8 days of SLAMing added to salt levels. Visually looking into the tube I see chlorine being made but was surprised when FC didn't go up at all after I turned it back on at 100% having completed my SLAM and it ran overnight.

 

[sendsley]

Here are the numbers:

Last night 10:05pm FC 4.38
SWG running all night at 100%
840am today FC 4.24
SWG running all day - pool was used briefly, very hot day (near 100 degrees), about 10 hours of direct sunglight.
505pm today FC 3.52 CC 0.23
Measuring water directly from return line FC 3.64 CC 0.07

Salt 3230

CYA was 40-45, nearly 3lbs of Cyanuric Acid has been adding in past 24 hours - still a bit in the socks left dissolving.

So...what does all that mean? I'm good at 100% maintaining FC around 3? Do I need more salt? Is my SWG failing? Something else?

Thanks

 

[JasonLion]

It is likely that you need to SLAM the pool.

Your daytime FC loss is plausible, and likely due to the low CYA level. But overnight your FC level should have gone way up.

I would go ahead and start SLAMing the pool. But if you want to double check, turn the SWG off in the evening and do an overnight FC loss test (described in the How To section of Pool School).

 

[sendsley]

I know that's the go to response around here but as I stated I just completed a SLAM (8 days, gallons of bleach), passing all required steps to be "done" 2 different nights. So I don't understand how that's the issue. I'm trying to diagnose a potential problem with salt level and/or function of my SWG.

 

[Richard320]

Running all day, I'd expect the FC to be way up there. I can't find any technical specs on that SWG, to see if maybe it's putting out all it can. http://sgschlorinators.com/

It could also be low CYA.

 

[sendsley]

Is there a direct correlation between salt level and chlorine output? Or does the SWG work as long as it's in range?

CYA was measured at 40-45 a few days ago, 3 lbs was fed in through socks in front of return jets over the past 24 hours.

This is the manual for the 320, 300 is just the same http://sgschlorinators.com/wp-content/uploads/2011/12/Breeze-OM-2012.pdf

 

[Richard320]

The manual says "Breeze 320 Produces up to .78 pounds of Free Chlorine per day"

That's essentially 12.5 ounces which poolmath says should raise FC by 8.5 ppm in an 11000 gallon pool. That should be plenty - especially running overnight with no sun load.

I think it's time to repeat the overnight loss test, with the SWG off. If you aren't losing a bunch, then the SWG is shot.

 

[sendsley]

Thanks. I added 80lbs of salt tonight to get it up over 4000 and into the SWG recommended range, if it doesn't pick up after that I'll start exploring warranty replacement options. Ugh.

I will repeat OCLT tonight.

 

[sendsley]

Very heavy rain late last night threw my testing out the window. Trying OCLT tonight.

 

[aussieta]

your signature lists taylor 2006 test kit but no way did those results come out of that kit
repeat all your tests with the taylor kit including OCLT with SWG turned off

 

[DogsHouse_MyPool]

How are you measuring salt level? You need a test source besides the SWG. SWG control panel readouts can be off quite a bit, especially if the cell is not working right. I wouldn't add more salt until you get a confirmation from an alternate test method.

 

[sendsley]

My signature also lists the LaMotte Color Q 7 Pro test kit.

My salt readings come from Aquacheck test strips, my SWG does not readout salt levels.

Last night, passed OCLT again with SWG off all night.

 

[sendsley]

UPDATE
I don't think the SWG (SGS) is dead but it seems like it's dying???

Here are some recent numbers
7/8
745am FC 6.95
SGS on Boost all day
310pm FC 5.28
1015pm FC 5.09
Actually lost chlorine during the day on BOOST

I turned it off overnight to make sure I had no algae eating up the chlorine.

7/9
745am FC 4.65 (minimal loss with the SGS OFF)
SGS still off during the day
630pm FC 3.15
Turned SGS back on at 100%
1025pm FC 3.31

Left SGS on overnight at 100% (would expect a decent boost in chlorine at 100%)
7/10
SGS still running all day at 100%
830am FC 3.56
5:15pm FC 3.58
10:05pm FC 2.74
Turned on to BOOST mode at 10:15pm

We'll see what the morning brings, on BOOST mode overnight I'd expect chlorine levels to be close 5ppm?? Is that fair if it's truly working at full strength?