With timed dripper systems and flood & drain systems does the medium ever get dry? I ask because my reading suggests that cannabis medium should get dry between waterings. At least that's my perception of the information. But if there is simply a timer and no micro-management of the grow it would seem that the soil is likely to be always wet. Soil that's always wet = overwatering, which we all know is "bad." Please help me with this apparent contradiction. Thanks.