Pentair SWG Questions

[jeffbg]

Folks,

I keep a log of my pool for comparison year over year. This year so far I've had to run my SWG at a setting quite a bit higher than last year (but our weather has been weird too). There are some differences and I'm wondering if that is playing into things. Last time I did an overnight drop test it was fine.

I did an ascorbic acid metal cleaning job earlier in the season and the pool looks great, but now of course, I've got iron floating around in my pool. My SWG also reports a much higher salt level than I get when I used a test strip (about 1000 ppm higher than the strip).

So I'm wondering if:

1) The iron and other solids (we have super high calcium levels in our water and I use borax too) could cause the SWG not to run as efficiently.

2) If the SWG thinks the salt reading is so high, is it turning down the current applied and thus getting less Cl into the pool as a result? Any way to recalibrate it closer to the strip?

Thanks!

- Jeff

 

[JasonLion]

Neither iron or salt would have much of any effect. However, the CYA level can make a huge difference, as can scaling on the SWG cell plates.

 

[jeffbg]

Neither iron or salt would have much of any effect. However, the CYA level can make a huge difference, as can scaling on the SWG cell plates.

CYA levels are plenty high at least 80. No scaling to speak of on the plates.

Worth trying to calibrate the cell if that is possible?

Maybe I really have some latent algae problem I've not detected?

 

[JasonLion]

Calibration the SWG salt reading won't make any difference at all.

The next thing to check is to do an overnight FC loss test to see if there is an organics issue.

 

[jeffbg]

Calibration the SWG salt reading won't make any difference at all.

The next thing to check is to do an overnight FC loss test to see if there is an organics issue.

Overnight loss test looks good. I ran the AM test twice and got within 1 drop each time. My cell is going into its fifth year, but is way oversized for the size of the pool -- IC40 on a 15K gal pool, so I usually run it say around 25-30% depending on the time year, sometimes much less. Nevertheless, maybe it is starting to age and what I'm seeing is that and a combination of other factors not present in previous years. I do have a lot of tree litter and such that falls into the pool this time of year and our weather has been odd. The pool last night was virtually free of such litter since I have it a good scrub late in the day yesterday, so it would have had minimal impact overnight, but perhaps during the day with the winds, more CL is required to stay on top of things.

 

[JasonLion]

I'm running out of suggestions. If the cell was failing the salt reading would tend to be lower than actual, rather than higher than actual.