This link may be something you're interested in.
Also, This post in the container gardening forum is a good resource and explanation.
Additionally,this thread, also in container gardening, give proportions for a good veggies medium.
Of course, feel free to ask more questions here, but if a static system is what you're after, container gardening may suit your needs better. you may want to also consider a drip system where you'll manually put the nutrient at an elevation higher than the drippers (gravity will water the plants). lots of possibilities, so ask away.

Is there a reason you want to avoid water pumps? They start at about ten bucks and if you don't have that much money (fwiw right now I don't either), then you are not going to be able to afford to build very much in the way of hydroponics setups.

just get some 5 gal buckets and a aquarium air pump and a couple of airstones. you will also need a couple of 3" net pots some hydrotron and some GH flora series nutes... just add plants and it will do the rest.

you should find out whats in your local water. you can probably get a report from the water comp. my water is full of sodium chloride, so a run to waste system is best to prevent a toxic build up in the medium. you really cant get much easier than a run to waste drip system and if you dont want pumps, use the gravity feed system. i mix the nutrient in the tank and feed every 2-3 days. use plain water the rest of the time. the peppers are in 1 gal bags. they require daily watering. when the temps go up, use 1/2 strength solution.

pepper pic.

rebelhead,
can you please explain what is going on at the discharge from the trashcan in the first picture?

it is just valves and a filter. the water hose supplies the water. the gate valve is used to control the water pressure. the trash can holds the nutrient.

does that much elevation (of the trashcan) give you enough pressure? I was at the hardware store the other day and the drip emitters said 25psi was there operating pressure.

pressure compensating drippers need about 10 psi to open. i used non pressure compensating flag drippers. the more elevation the better. when a dripper says 4/liters per hour that is at a pressure of 25 psi. less pressure, less output. the tank is 32 gallons and it takes about 4 hours to empty. running 30 4/liter per hour drippers at a time. the tank is on a hill so it is actually higher than it looks.

Very nice!!!

As far as mixing fertilizer in the water, do you think the gravity fed systems are more prone to clogging? I think it would be fine with a powdered or a liquid fertilizer. But I wonder if I would clog it up with Molasses, which runs fine through the 10 psi drip tape in my garden.

i have run molasses through mine. the drippers have never clogged, but i run straight water with the pressure turned up to clear them out 4 days a week. i believe they would clog if i didn't.