Why do I need to measure EC if I don’t have a salt problem?

If you use fertilizer, you are adding salts continually. Unless your turf is consistently 100% perfect, any problem areas may be because of a “salt problem” or better stated, a salinity problem—you just don’t know if they are from overwatering, under watering, over fertilizing, under fertilizing, incorrect fertilizer application, or some cultural ailment, etc. The only way to know is to measure salinity along with moisture and temperature, and to trend this information over time so that you see an issue before the symptom shows up in your turf system.