Materials:
1 45 gallon water trough from tractor supply ( to store the fish) $39.99
1 15 gallon water trough from tractor supply (to plant our plants) $21.99
1 50-80 gph pond pumps from Lowes (to push the water from the fish tank to the plant tank)- $17.00
3ft of clear tubing (to connect the pump to the upper tank)
1 Locknut PVC fitting
Drainage Stone
First you need to drill a hole in the largest tank, and attach your PVC fitting. We used PVC glue and scilicon to do this. The you fill the lower tank water, and submerse your pump (after connecting the tubing). If you do this correctly the water from the lower tank will come through the tubing. Place the tubing in the smaller tank (after setting it directly about the lower tank) and then fill it with your drainage stone (or clay pebbles, or styrofoam....). I would then fil the top tank to the rock level with water. You should have a flowing system.
I would wait 24 hours to add fish. If you do this, the chlorine should have evaporated enough to not harm them. You can also add pond water to jump start the system. Also, you may want to rinse your stone!
In the end, you will have a tank of water and fish located under a table. The submersible pump will pump water throught the clear tubing into the upper tank. I filled our upper tank with drainage stone. We have only planted lettuce in the upper tank, so far. Gravity creates water flow through the locknut fitting into the lower tank. Pretty, neat, efficent project!