SWG effectiveless seems less this year

[Fuldo]

I've had my RJ-30 SWG for about 16 months now. I've closely tracked water chemistry, chemical additions and SWG settings since the installation so I have good history. The SWG has served me well and was perhaps more effective than I expected, likely because of my screened pool enclosure. Very little, mostly acid and some salt, has been added to the pool since the installation of the SWG, it simply didn't require it.

This winter and early spring the SWG performance and settings required mirrored those of 2019. That changed the last four weeks or so, I've been bumping SWG output well above last years settings for the same time periods. My cell is now "running" 216 minutes a day and last early April it was only running 108 minutes per day to hold the same FC level (about 5). My CYA is 50 and was 50 a year ago. Temps and water temperature are also almost identical to last year. The SWG drive voltage and current are virtually the same as last year and I pulled and inspected the cell and it l can't tell it from new! The water is and has been perfectly clear for years so I've never elevated my FC above "normal". I seem to be loosing little or no FC overnight. I'm wondering how to better understand this problem and if I should strive to solve it if it's solvable at all.

Has anyone noticed some deterioration is cell performance over time when the cell still looks like new? Should I try a "short slam" to help ensure there isn't any underlying algae issue? Any other ideas or thoughts?

 

[mknauss]

From your write up, you are using double the chlorine this year versus last. That is a huge change. That is correct, right?

If you are assured your CYA is the same as last year, I would suggest a quick hit of SLAM level FC for a couple days to see if that gets your FC use per day back to your expected level.

 

[Hootz]

After reading that some members here with Circupool units are getting more production with higher salt levels I have seen similar results. Last year I kept my salt level at around 3400... this season I bumped it up to 3800 and so far the production seems to have increased....I have lowered my cell percentage from last year. Check your salt level and consider pushing it closer to 4000.

 

[Fuldo]

Yes, in theory I'm using twice as much chlorine now as a year ago. That assumes the SWG is generating as well as it did a year ago. Before I removed the cell for inspection I watched it as it was generating and it seemed the amount of "fog" (chlorine gas) was less than what I'd remembered when it was new. That is why I was thinking the SWG might not be as efficient as it was for some reason.

I just checked my salt level at 3400 and the SWG controller shows it at 3220. This is maybe 300 points lower than this time last year and the cell current shown on the controller is a little less than last year. Based on my home energy monitoring system I think the cell was drawing about 140 watts some time ago when active and now it's drawing about 100-110 watts when active. This is maybe another sign the SWG output could be lower for whatever reason.

I'm bumping the FC to 20, adding 40# of salt and bringing the PH down from about 7.9 to about 7.5 and see what happens next. I'm not sure what other options I have. I wonder if the noise I've been hearing occasionally from the SWG controller is somehow related.