This is a nesting flower pot that can be used as a self watering pot for plants that can thrive in that environment. If you don't want that function you can just fill the base of the inner flower pot with gravel/stone and the basin will still act as a water catch and decorative feature. You can also just use the basin itself, without the inner pot, since it does not rely on the inner pot for any support or structure. I use these for growing small herbs and starter plants indoors.
The key to a successful water tight print is eliminating shapes that FDM printers do not handle well which is why there is only a minor fillet (curve) at the bottom of the basin and everything else is as smooth as it can be. All drainage slots are cut vertically to aid in successful printing. Additionally, as most people are using .4mm nozzles, the walls were designed at 1.6mm to allow for 4 even layers (2 outer/2 inner) which aids in sealing the print. I designed this because I found that many other options available here involved complex shapes and features that were nice to look at but difficult to consistently print water tight. This shape may not be as exciting as some of the other pots here but it is water tight and fairly simple to print with any material. Details on printing below.
This overall dimensions are 125 mm tall with a 100 mm diameter for the outer basin.
The tall basin is a full 125mm so it covers the inner pot. (left most pot in photo made from stained wood PLA)
The short basin is 95mm tall so the inner pot is exposed. (all three other pots)
I printed this using standard temp setting for the materials I was using which are generally on the high end of the recommended temps. The walls are 1.6mm thick and as such are intended to be printed using 4 layers with a .4mm nozzle (2 interior and 2 exterior). The key to a water tight print is to set all of the layers up to the vertical walls (past the bottom curve) to print slow. For me that was the first 6 layers at .28mm resolution and 20mm print speed and the rest at 40mm speed (inner and outer walls using Cura). The 100% infil will only affect a small area where the cylinders intersect to ensure a solid water tight bond. Print vertically as they would normally stand, bottom to top, with no supports.
I used a concentric bottom pattern (Cura option) which I also believes helps it print waterproof since there are half as many and much less severe direction changes during the bottom print then if you printed it using lines.
It was successful and watertight using Hatchbox PLA, Hatchbox Wood PLA, Makergeeks Crystal PLA and Makergeek Maker PLA.