That is somewhat of a general question. There are many variables such as size of pot, temp. and humidity in grow room, and size of plant.
I just go by how my plant looks, if it starts looking wilty, I water it. Water it good when you water, having some water run out of the bottom of the pot.
Watering is one of the hardest things for most new growers to grasp, it was for me anyway.
Good growing!!