You got it right about flushing! Flushing washes all the excess nutrients out of the soil and allows the plant to burn up the nutrients stored in the stems and leaves. Do you have Robert’s free E-book download on Growing Marijuana? It is available on this site. It will explain a lot of things very clearly.
Something you might want to keep in mind for later grows, as you water and feed during the life of the plants, give them enough room under them to drain about 20% of each feed/watering (if you are in soil of course). It helps keep the pH at a steady level (VERY IMPORTANT) and it also makes it easier and not so important to have to flush so much. It also seems to make the plants grow much better. I started doing about 20% over what the pot holds this grow and the results have been WAY better. I am in week two since germination (Veg day 7) and have never had a plant grow so quickly and stress free. I mainlined it (my journal is “Super Silver Haze in a Grow Box”) and it recovered in a day with no stress noticed on the plant. Read Robert’s book and you will become a better grower. Also, he has a nice section on harvesting, drying and curing your harvest in the Guides section since you are so close to that.
You came to the right place for help. I started using this site two years ago and my growing has gotten way better. Good Luck on your harvest. We all help each other here. Let us know if you have any other questions. Jerry