Overwatering is not about quantity or volume, its is more about frequency.
If you water everyday, chances are you are overwatering. It shoukd be every 2nd or 3rd day depending on how much your plant drinks, the humidity, what kind of pits your using and how much airflow you got going in the tent.
Honestly the best way to check is the finger test. If it is still moist on top, just dont water that day.
Also if your light is putting out too much, it may look like you overwatered, try turning your lights down that helps alot too.