This system can be used indoors or outdoors, can be used as a cloner or to grow veggies and plants.
This is the first set I build, 5 years ago.
It is still perfectly working.
Step 1: List of materials
The inside rim is important, as the PVC tubing will rest on it.
1/2 inch PVC tube
4 pieces 1/2 inch PVC tube 90 degrees angles.
one T junction 1/2 inch
an aquarium pump
a 15inch long flexible water hose 1/2 inch diameter.
6 or 8 empty yoghurt pots
a 24 hour timer