I just was playing with the pool calculator and noticed that adding 2ppm FC raises salt levels by 3ppm via sodium hypochloride (bleach). so, you won't necessarily have to replace water yearly or bi-yearly for some people, but you would have to eventually lower your salt.
I figured ~1 gal/day in my pool yields 3ppm salt per day, I don't plan on closing the pool down in the winter and I'll probably cut back on the usage some over the winter but still I'll expect to use at least 300 gal of bleach this year. that comes out to ~900ppm salt added assuming I only use 300 gallons. I've already used a good 50 gallons if not more and thats 165ppm right there. I measured my salt via test strips and got a reading of 600ppm.
my question is, when does one know when there is too much salt in the water?