I'm sorry, but you are misinformed about salt systems on pools. THEY ARE CHLORINE POOLS, the chlorine is converted from salt. You can take a normal, off the shelf chlorine test kit and check the water and find that it has chlorine in it. On the system I had, I could flip a switch and it would automatically increase the chlorine level to "shock" levels. You might think that algae would grow most during dark hours, but it actually will grow more readily during daylight, so it is recommended that you run your pump and filter at least 8 hours per day with most of that being in daylight hours.Seriously if you mix your shock with 5 gallons of water and pour it around the outside stiring it with a broom eairly in the morning. The sunlight burns the clorine out by the afternoon. You don't have to wait all that long. With the water at around 80 degrees and up where bacteria and viruses can thrive I just would not feel safe in a salt system. Most hot tubs don't allow chlorine products and I've also considered them unsafe. Once at the Holiday Inn several people were in the hot tub togeather and this guy said do you want to see why their going to cut my leg off and he pulled it up and it was gangreen. People litterally jumped out running. Chlorine is a must for me.
There is nothing unsanitary about salt water pools in a residential setting. You won't find many in commercial pools yet though.