I'm having a bit of a mental quagmire in understanding my salt cell's actions recently.
Basically, when water temp hit ~65, I kicked the cell percentage on and up. I then added a gallon of bleach to kick FC way up so that I could be sure to be operating at a high level if something was wrong as the cell was 'turned back on'. I've done this every year, just as a protection deal.
So several days ago, FC was at 16 and salt cell was at 25% Water temp has been between 68 and 70. Salt cell reads 3150, Salt test (Taylor) reads 3200. CYA at 50.
I wanted to test that the salt cell was really pouring in the chlorine if necessary, so I kicked the cell to 80%
We had several days of sun, then rain, then sun, then wind. FC has never dropped below 12.5, so there's obviously been some production, but at 80% on an IC40, and 12K pool, I'd expect FC to be climbing because that's way more output than it needs even on the brightest summer day.
So is the failure of a salt cell gradual or wham...all of the sudden? I have found a potentially applicable discussion here but there was no real consensus as to if the failure is sudden or over time. Maybe it is variable?
I did take the cell off and look for scale and there's a few granules right at the end of about 2 blades, but the rest is clean.
I can't shake the spidey sense that the cell should be performing higher (with the metric being a rising FC) than it is.
Pool was installed July 2012, so salt cell would now be in it's 4th year.