*cracks knuckles*
1 gal 10% = 5.6 FC for 18k gallons
$5 jug = $0.89 per FC
$6 jug = $1.07 per FC. (Walmart is a hair over $6 after tax)
$7 jug = $1.25. (Lowes is $7.79 plus tax)
Home Depot ($10 ish, just don't even)
We have found circupool to greatly overestimate their production #s, on their chart at DSP (them) and they are head and shoulder above the rest. (Per them).
I will be extra conservative and instead of 2lbs a day, I will use 1.4lbs which is the IC40 output that at its worst, it matches. It very well could do better and that's all gravy if it does. But using 1.4lbs per day for 10k hours:
9.3 FC per 24 hours
3875 lifetime FC
$0.26 per FC at $999 for the unit.
It's the equivalent of 693 jugs that would cost $3465 at $5, or $4158 at $6. Plus sales tax for even more out of pocket. ($3769/$4523 in NY). With the SWG you're only paying sales tax on the $999, for even more, more savings. Said tax savings alone will easily cover any salt needed for a long time.
Not lugging 693 jugs is PRICELESS, trust me here, you don't even know.
@PoolStored told me he'd fill in his pool on day *3* if he ever had to go back.
You could pay $1500 for a full PB install, plus the $1k unit and still be up $1300. The controller lasts for several cells so you only need to replace the cell, increasing your ROI longterm at the $0.26 per FC rate for those cells.