Flushing is only for emergencies, like if you measure your nutes over your pots and accidentally spill full strength in the pot (it happens to the best of em) Or if you use synthetic nutrients and you need to wash salt build up out of your soil. It's not a standard procedure. The "flush" a lot of people refer to we call a cleanse here at AFN. That's when you just water your plant with plain water the last two weeks of it's like to help it clean itself out. Chad's right about your young plant, you may stunt the hell out of it flushing at this early point and for no reason.
Hope that helps!