@Ellis Mendo mix is precharged with enough nutrients to last about 4 weeks if you do not wash them out of the pot by over-watering. You do not want run-off until you start fertilizing. Lets get a couple of terms defined here so there is no misunderstanding:
1. Watering = just PHed water.
2 Fertigating = water plus nutrients PHed.
Then around the fourth week you need to start fertigating. When you do start fertigating you want to add enough to the pot slowly moistening the entire pot until you get about 20% run-off. What is meant by that is if you fertigate 100 ounces you want 20 ounces to run out of the bottom of the pot. You do this to carry any excess salts (fertilizer) out of the pot. This prevents a toxic build up.