HI all. I've got some questions that have been filling my mind over the last week or so. I have a 30k vinyl liner pool with a Pool Pilot Digital/RC-42 setup that's open for 5.5-6 months/yr. This is the third summer with the pool. We've been using a solar cover for most of the summer, but 3 weeks ago removed it as it was starting to deteriorate. I noticed last week my FC levels didn't seem to be keeping up using the same purifier output percentages as I've historically used with no solar cover. There are no warnings messages to indicate a problem, but I got stats off the Pool Pilot Test Menu:
Salt - 2900
Temp - 80
Amp-hours - 11,344
30V 6.1 Amps
So I added 3 bags of salt, noticed some improvement in the stats, but also read here to have the water tested at a pool store to confirm the salt calibration. Pool Store came back 300ppm lower than what the Pool Pilot was reporting, so I adjusted the calibration and added more salt. I also cleaned the cell even though there was no visible calcification and the blades all look equal in length and width at the edges. New stats are:
Salt - 3400
Temp - 80
Amp-hours - 11,500-ish (going off memory)
27V 6.5 Amps
I run my pump on low speed 24x7 and the purifier output % is currently 32% at Power 2. The water is crystal clear. but just to be certain, I shocked on Sunday and passed an overnight chlorine loss test. My levels are:
FC - 5
PH - 7.5
TA - 80
CYA - 60
CH - 90
The thing that's perplexing is I keep having to nudge the purifier % up in order to maintain FC of 4-5. I know I should still have plenty of years left on the cell, so I guess my basic question is, as the cell ages, is it normal to have to find a new/higher purifier output % as I seem to be experiencing here? The weather has been remarkably consistent in terms of temperature and sun for the last week+ here.
Any other ideas/thoughts on additional steps I should be taking to confirm something else isn't brewing (such as a premature cell failure)?
Thanks in advance. Hopefully I'm just way overthinking all this (as I've been known to do).