Bulkhead fitting for a 1/2" poly hose

thingiverse

You'll be able to make a connection from a half-inch poly hose to a tank. Instructions You'll need to add a garden hose washer so that it doesn't leak. Print with one hundred percent infill or the bottom of the connector may break off as you tighten down the nut. Update - I uploaded a newer version (v05) that makes the area around the washer slightly thicker, the hole in the middle smaller (so the walls are thicker), and the nut smaller (so it puts less pressure on the threads when you tighten it down). A regular hose washer still fits but you'll need to push hard to get it over the last bit of plastic.