Wow ! You got everything you need except seeds.
As far as lettuce is concerned . . . pick the ones you like best. I usually buy a packet of mixed seeds. Exciting!
I take about 4-5 (tiny) seeds and sow them in their final position in perlite. Keep the best shoot. Cut away the ones you don't like.
You should keep the seeds in the fridge (in a little pill box). Even then, they wont last more than 6 months. So, put a date on the box.
A lot of people experience problems with spinach, so I recommend Swiss chard. The young leaves are delicious (raw!)

Don't worry. Just have fun.

Thanks! i do have a degree in horticulture but I am definitely not used to dealing with things like EC, etc. I've been working with soil for as long as I can remember it seems... so in that respect I, like many experienced gardeners, have developed an intuition for things...I am totally on board with the whole concept of organic hydroponics...especially systems that emphasize sustainability (like some aquaponics systems, and other methods that make use of every by product). Hydroponic systems have the potential the be completely(or nearly so) environmentally responsible, being an enclosed system that recycles its byproducts and doesn't have to release any contaminents or waste(if the ideal setup is used) but now we must deal with the chemistry ourselves. I think it's all very exciting, especially when you think about the aspects of reducing soil-borne pathogens and increasing root oxygenation/drainage when an artificial setup is required. Frankly, when it comes down to it...I have so much to learn about hydroponics! I'm lucky to have a local store that specializes in both hydroponics and home-brewing (another hobby of mine!) and with each purchase I recieve a free issue of Urban Garden Magazine and/or some other mag. but I feel I need a greater education than these publications can offer and unfortunately I dont really have the cash to shell out for those Grower's Edge books or really anything for that matter.. (I'm a college student). So any links/or ideas/tips/free lsources of reliable lirerature are appreciated! I'm willing to trade for used books as well!
Much love,
Jen

You won't be sorry haven joined this forum. It's arguably the best in hydroponics.

BTW: I think you could also try to grow Watercress in your system.

Hydro systems plug up with organic nutrients because liquid passages are small. Biota that come with organic nutrients will begin to grow and plug emitters/pumps/pipes.

Organic chemicals are all the same no matter their physical form.

thanks for all the input! Willard, I wasn't going to put raw organic materials in, just nutrient solutions derived from natural sources.

Though you think organic is the way to go, eventually you'll find your way to the darkside(liquid chemical nutrients)and when you do, you'll want to read This article to learn about calculating nutrient concentrations.
don't feel bad. Many a seasoned organic soil gardener has come to hydro with the intention to maintain their organic philosophy only to find mechanically produced chemical nutrients offer better control and prosperity for there systems. Since the systems are enclosed and can be recycled, they're still very friendly to the environment. At least from the end users perspective. I have no idea how the manufacturing process affects the environment.

i have a 4 bucket system (dwc) growing four chile pepper plants. i use botanicare pure blend pro and have never had to change an airstone yet (started in may 2009).