Now I have built a custom Earthbox a trough that functions as a self watering pot.
It's a little special thing about this is that you have a waterproof cover that one places over the Earth in order to reduce evaporation and if you have the open air to avoid getting rainwater in Earth/trough. It also adds a manure string in the pot so there's nutrition available for a long time to come.
Here you can see a video when I build my ChiliBox by a murartråg from auto parts store on 65 liters.,two tubes of various dimensions, a foamed pvc plastic disc and a waterproof fabric with elastic sewn around the edge so it becomes a cover.
Cost about. 200:-
Do you have mobile so go to this link http://youtu.be/PhvHWHwzYYM