tikitoker's got you on the right path with his advice here. And i would second the call to organics. Since you haven't used any synthetic ferts yet, flushing might not be your best bet. It doesn't do anything to flush soil in an organic grow because you aren't forcefeeding your plants synthetic, salt based nutrients. Rather, you tend your soil-food-web to allow the plant and the microbe herd to exist in a symbiotic relationship. plant exudate feeds microbes, microbes feed plant, big happy family. check out the organics forum for a more full explanation, get your hands on a copy of
Teaming with Microbes. It's actually a much easier way to grow once you understand what you're doing.
FFOF will take you through 2-4 weeks depending on the strain but after that you're going to need to add nutrients in some way. AACT and nutrient teas are a good option, and if you don't want to buy raw ingredients, there are some liquid organic fertilizers out there that you can make teas with quite easily (e.g., Earth Juice). Best way to build your tea brewer is a 5 gal bucket with lid, air stone, and ecoplus commercial 1 air pump.
The only other piece of advice i've got for you is always let your tap water dechlorinate if you're using that as your water source. Chlorine will kill off your herd. As of now, chloramines --should you choose to get super anal about something you don't really need to get anal about--can be effectively removed using (i believe) 1000mg/gal vitamin c.
Next grow build your own soil (use subcool's supersoil recipe thread and related information to start with, but pay attention to why your adding each item in the recipe).
hope this all helps,
be easy,
