how often to water will be specific to ur grow set up, u need to find a middle ground where ur not over watering, or under watering. If u have time to test it out, turn ur pump on for 15 mins, and then unplug it, check back periodically until u see the roots are starting to dry up, now u know when the pump needs to go back on. When the plant grows and start to flower i would water more frequently as the plant will absorb more. When i hit week 3 in flower my drippers are on for 15 and off for 45, i used to run them 24/7 but i realized it wasn't necessary.