Hi everyone! I'm putting together a grow bed with a bell siphon in it. I am using 3/4" PVC piping, connected into a male adapter, connected into a 3/4" bulk head. I couldn't find just grommets at the hardware store so that's why I got the bulkhead. The grommet isn't the kind that fits onto both sides of the plastic. I drilled the hole using a spade bit that measured 1 1/4" and it fits snug. I had…