I designed this in Fusion 360, as a hydroponics pot to grow herbs and lettuce in an unused glass mason jar (top pic), or water bottle (bottom pic). The design should screw into the mason jar / water bottle and then you can start growing.
Step 1: Download and Print
Download the STL of the file and 3D print it (1st STL for mason jar and 2nd for water bottle). I recommend normal resolution in PLA. I only have renders of it as I have not yet had time to print it myself. The larger object should fit on a standard size mason jar, and the smaller is to fit a water bottle.
Step 2: Assemble and Grow Plants
Once printed, screw onto the jar, and fill the pot with soil, and plant the seeds. Then unscrew and add a mix of water and nutrients to the jar, until it is quite full. Then re-screw on the 3D printed object, and place in a warm sunny environment. If the water in the jar gets cloudy or infected, remove it and replace, as well as if it empties below the line of the pot. If you are having difficulties with the roots of the plant trying to photosynthesise, then place the jar in an open box, paint it, or use a coloured jar.
Hope you have fun!