>>1449168It may be a bit late, but I did find this,
https://www.instructables.com/id/self-watering-tray/It is just a terracotta pot, seed tray, and open cell foam to make an automatic capillary watering system. I think that if I were to do it, I'd put a piece of plastic over the foam then cut holes in it for the pots then cover the terracotta pot completely with an upside down pot that doesn't have holes. That way it'd reduce the amount of evaporation.
