You will need a few things:
5 x Styrofoam "fish boxes" (approx 18"x40"x18 WxLxH), two with lids (FREE!)
20L (5gal) plastic bucket (FREE!)
Solar pump (cheapies on eBay for $15)
16' of 3/8" poly tubing for drip irrigation (about $10)
2 x 3/8" tee
2 x 3/8" elbows
3 x 1/2" drain fittings, sometimes called bulkheads ($10)
16 x 1/4" drip tubing "taps" which are punched into the poly tubing ($10)
Growing medium that doesn't clog (Coconut husk chunks work great!) ($10)
Mesh screen (FREE!) use a broken screen door
A stone to weigh down the reservoir lids (FREE!)
You will need the following tools:
3/8" drill bit for drilling holes in styrofoam for poly tubing
3/4" drill bit for drilling holes in styrofoam for drain (bulkhead) fittings
Sharp screw or other poking tool for making pilot holes in poly tubing for the drip taps that feed each plant
The styrofoam fish boxes can be found in the dumpsters of seafood stores. They are used to ship large salmon, etc, and are usually thrown out back. Be sure to check for leaks, as they need to be water-tight.
The buckets can be found at sandwhich shops. They are used to ship pickles.
The solar pumps are found on eBay.
The drip tubing and fittings can be found at hydroponics stores, or home improvement centers (Home Depot, Lowe's) in many regions.
The 1/2" drain fittings, or bulkheads, can be hard to source. Hydroponics stores will be your best bet.
For a growing medium you can use wood chips. I use coconut husk, which is rather chunky and was on sale for $0.50/cubic foot.
Criterion for media:
* Large sized, so it won't wash into drains, tubes, and pump
* No coloring
* Gives roots something to bite into
* Retains moisture
Plan your system. Determine which side you want the reservoir on.