I just forgot to turn my ATO back on for 4 days and my salinity went from 1,0255 to 1,062, so not exactly a catastrophy. My tank is 75 gallons.I never keep my salinity at 1.025-26 SG due to evaporation. Just in case my ATO stops working at 1.023-24 will give me enough time to correct it if it should raise higher than my initial Salinity Range.