What determines an optimum EC level is the plant's transpiration level, not the watering cycle setup by the grower. As far as the watering cycle is enough to keep water potential at a good level that won't constrain transpiration. Temp., humidity and CO2 level (or directly the three parameters together on the VPD (Vapor (water) Pressure Deficit) factor in the most.
The higher the transpiration rate, the lower (same amount of mg of nutes total, but dissolved on more water) EC should be.
So independent of watering schedule, EC must be adjusted according to how much water a day plants are transpiring: how much gals of salts that they consume on a daily (or weekly) basis. The higher the rate of transpiration, the lower the EC.
Transpiration often is greatest in hot, dry (low RH), windy weather.
The higher the transpiration rate, the lower (same amount of mg of nutes total, but dissolved on more water) EC should be.
So independent of watering schedule, EC must be adjusted according to how much water a day plants are transpiring: how much gals of salts that they consume on a daily (or weekly) basis. The higher the rate of transpiration, the lower the EC.
Transpiration often is greatest in hot, dry (low RH), windy weather.
