I have seen a airoponic system being sold on E-BAY for a couple hundred bucks,that was made up using a 20gal rubbermaid tub W/top.Cut holes in top for plants(up to 8).
THE GUTS:
1-light timer multi-cycle and adj length of cycle
1-small air pump,tubing & air stone(10gal aquairium style)
1-250gph fountain pump.
3'-3/4"pvc pipe
1-1/2"male thread X 3/4" pvc pipe adapter
1-3/4"pvc tee.
1-3/4"pvc cap
2-3/4"pvc couplings
1-3/4"pvc pipe X garden hose male adapter
1-garden hose threaded cap
1-1/2"male pipe thread 90* X 1/2" slip tubing adapter
2'-1/2" clear tubing
pvc glue & cleaner
small tube of aquairium silicone sealant
4 - 3'-7' full circle mister heads(micro mister watering systems 1/4" tubing)
THE ASSEMBLY: 1: cut plant holes into lid,center holes between edges & center of lid;leave center uncut(don't forget to cut a small hole for pump plug/air tubing).
2: drill a 1" hole at each end of the tub(just below handles & above groove).
3: drill a 5/8" hole a 1/2" up from the bottom on one of the sides.
4: assemble 1/2"male X 3/4" pvc adapter into pump and place in center of tub
5: cut 2- 1/4" sections off of the 1/2" clear tubing & force one onto the threads of the 1/2"male 90* X slip tubing adapter(pushing it all the way to the back of the threads)apply a bead of silicone around the threads at the tubing and insert into the 5/8"hole apply another bead of silicone on the inside of tub & force the other piece of tubing over the threads pushing it all the way up to tub wall.(this is the water level sight tube)
6: assemble & glue short 3/4" pvc nipple into the 3/4"pvc X garden hose male adapter and force it through the 1" hole above the sight tube fttg, glue a 3/4" coupling onto pipe on inside make sure coupling fits tight against the wall(sandwich wall inbetween fttgs)Repeat on other end using pvc cap & coupling on inside
7: align 3/4"pvc tee over pump fttg measure & cut 3/4" pvc pipe to reach each end fttg,dry fit manifold together & measure/cut raiser pipe from pump to tee.glue together.(if you devolope leaks around coupling/caps just apply a bead of silicone around them)
8: determine 4 center points along top edge manifold,drill 3/16" holes at those points.
apply a little glue to the mister heads and force/screw into holes.
9: install 1/2" tubing onto fttg at bottom make it long enough to reach up under the handle,flush pvc shavings out of the manifold through drain fttg & install hose cap on drain fttg.
10: install air stone into bottom of tub(keep it away from pump)connect to air hose/pump. set timer for water pump for your determined cycles/length of cycle.Fill 1/2 way up with your favorite nutes,plug it in and your off