Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4936819.

I wanted something to continually water a pepper plants I bought recently. After seeing https://www.thingiverse.com/thing:4506595 and https://www.thingiverse.com/thing:3954510 I decided to design my own version. Designed to print in vase mode, You should adjust the parameters in the FreeCAD file to fit your planter/bottle combination. The STLs provided are for:

• 28mm bottle opening, 25mm bottle throat length , 110mm planter bottom diameter, 0.8mm wall thickness (external perimeter extrusion width), 4 bottom layers, 0.3mm layer height(1.2mm bottom thickness). 3h print, about $1.
• 28x25x85x1.2 - yellow one, new design.
• 28x25x85x1.2 - old design For proper slicing of planters supports you need to adjust "Print settings/Advanced/Slice gap closing radius" to 0.005mm (this is for PrusaSlicer, no idea where is in the other slicers). I printed these in PLA and PETG but should work with any filament. For water tightness cover the resulting gaps with nail polish top coat.

This is reupload of my https://www.thingiverse.com/thing:4926062 because does not show in the searches. Also slight modification to the files for better printability (smaller resulting gaps)