UPDATE 6/17/2020 - Added a 4 inch version by request as well as copied the original to specify it as a 2 inch version.

UPDATE 3/18/2020 - Suggest printing upright to minimize support markings. Also recommend using a brim in this configuration. Otherwise the side edges are prone to coming loose during the print.

I recently took up an interest in indoor gardening. My kids and I built an NFT indoor garden out of 2" PVC pipe. Shortly after we got it running, I discovered a mosquito the size of a small hummingbird sitting in one of the unused holes having a drink!

I decided to create some caps for the holes. I did see gutter versions for NFT gardens such as https://www.thingiverse.com/thing:1688178, but nothing for PVC pipes. I designed this simple cap to fit snuggly in the holes while minimizing the footprint on the garden.

As uploaded, this design will work with standard 2" PVC pipes using 2" holes for 2" net pots. However, it's parameterizable, and should scale to other sizes. Just set "pipe_inside_diameter", "pipe_wall_thickness", "hole_diameter" and "cap_thickness" to your desired settings. (Note, all measurements in millimeters. Use 25.4 mm / 1 inch for conversions.)

The uploaded version should drop right into a 2" PVC pipe. The hole in the center is designed to minimize plastic use as well as give you something to grab when removing the cap. The lower end of the base fits half way down the diameter of the pipe to keep it from touching the nutrient flow. This should keep light and the critters out of your NFT tubes while being quick and easy to remove when your net pots are ready.