Stack-able seed planting pot

I made this pot to plant seeds one by one. Using it for dates currently. Their roots get deep so that is the reason for the shape. Would be good to have it in customizer scad format... one day i will learn that :)
One pot is about 23g and prints under one hour.

Update 2017.06.30:
Summer is here and pots are outside. They get direct sunlight for a few hours every day. Some of them melted a little :) but still holding up. Impressive from PLA.

Update 2016.10.24:
Added a little chamfer to t