This is a compact hydroponic system that I designed so it would fit nicely on my kitchen window sill and be printable with my Ender-3.

I have added the Fusion 360 project file, so that you can adapt the system to your liking. If you do, I would love to hear about your improvements :)

A water reservoir in the bottom holds a nutrient solution. The planter in the top is filled with growing medium (e.g. small stones or vermiculite) to keep the plants in place.

A small pump sits in the reservoir and is triggered several times per hour in order to flood the planter. Through small holes, the nutrient solution then slowly drains back down into the water reservoir. For my system, it takes about 50 seconds to entirely flood; it is easy to put it on a simple timer-controlled power plug. Of course, you can also add a water sensor that shuts off the pump when the planter is filled.

With the removable drainer, there is too much space for the water/nutrient solution to drain too quickly, so that it doesn't flood entirely. I fixed this by lining the planter with a waterproof foil (trash bag) which I poked with very few holes in the bottom so that it would drain slowly.

The part called Filter is meant to be draped in a piece of cloth filter held in place by a rubber band, so that larger particles don't fall down in the water reservoir where they could cause issues with the pump. Unfortunately, it is quite difficult to clean the filter without disassembling the whole construction. Let me know, if you come up with a better design :)

I've made a short video about the creation of this system: https://www.youtube.com/watch?v=FEDWGKrZ9ns