That pigtail looks to be a nozzle for the end of a water line. We use these where I work in one of the vessels when it goes through a wash cycle every 36 hours. You can also see them on fire sprinkler systems.
"Beer is proof that God loves us and wants us to be happy" Benjamin Franklin "Imagination is more important than knowledge" Albert Einstein "Stupid is as stupid does" Forrest Gump "Everyone has a plan-until they get punched in the face" Mike Tyson
That's exactly what the pigtail is. Wig the right flow, they spray great for sparing. Sadly, gravity is really tricky to get the right flow. I'm going to pick up a second pump to go single tier. I think that will do wonders for my efficiency.