We recently fostered a stray cat who turned out to be pregnant. With the kittens came an abundance of tiny cans that once held kitten food. I decided to up-cycle the cans into self-watering seed starters.
The walls of the soil basket are a mesh that I was hoping would keep the soil moist. (I didn’t fully trust that would work, so I added holes that could hold 6mm (1/4”) cotton wick that could be used to draw the moisture to the soil.) The lid snaps onto the can and the basket. I also added a riser to keep the soil basket from sitting in the water.
If I were to do it again, I’d find a way to make the bottom of the basket lift out, as I wish it was easier to free the little seedlings. I am pretty new to using modeling software of any kind and have been using Shapr3D for about four or five months now, so I’m pretty sure there are better ways to design what I did. Nevertheless, I really enjoyed it, and I hope you do, too! 
