In my classroom, we decided that we wanted to have a garden to fit in our long south-facing window. So I designed a garden that wouldn't need a pump running all day and had an easy bell siphon system to cycle the water every morning. The kids were so excited to see their lettuce growing like crazy!

Over the summer I moved the garden to my back porch. In the morning, I would slightly tip the garden to engage the siphon. When the siphon engages, I can set it down and let the whole pipe drain. Then I added new water with a bucket until just before the siphon engage point and then I'd leave it for the day. It grew all kinds of lettuce and fresh herbs for the whole growing season.

You will need a 3 inch drain pipe from the hardware store, a whole saw (for the net pots) and some aquarium grade silicone, also from the hardware store. Finally you will need some flexible PVC tube that goes from the garden to the bucket. The siphon end fits in the flange end of the 3 inch drain pipe. You will need to cut a channel for the bottom of the siphon but other than that, everything fits nicely together!

I also have made another siphon end that fits in the other end of the pipe, but I haven't tested that one yet.

Probably PET is the best choice. I printed mine with some PLA parts though and I haven't noticed any degradation over the course of the year.