the basic idea behind a self watering planter is to have a container inside a container that is able to draw water from the bottom and bring it up to the roots. This allows the soil to get as much water as it needs without over watering or under watering.



The most important thing about this concept is that some part of the top container be able to draw water from as deep as possible while leaving enough room to fill the bottom with water.



The cat litter containers are perfect since the spout, once reversed, will be able to draw water from the bottom of the the 2nd container while leaving enough room to fill the rest with water.



What you need to do though is create intake holes that will let the water flow through the spout.



I did this several ways,



First I cut a piece into the handle, this has 2 purposes in itself. First it allows water to go up and then it allows us to put in a tube which will allow us to add water (see next step).



The other way was to drill holes in the lid which can be screwed back on after.



I also placed some mesh at the bottom of the lid to make sure that soil wouldn't fall into the water. This is optional but I think it's worth the 2-3$ you'll spend for mesh.





