Instructions for connecting Hose:

There should be a threaded fitting on the outlet from the pump. The blue discharge tubing should fit snugly over the top of this threaded fitting. There should also be hose clamp in the box. This hose clamp is tightened around the blue tubing to hold discharge tubing on to the pump outlet.

Even though the fitting on outlet is threaded, the tubing slides over the top and hose clamp is tightened just below the threaded portion. There are not any fittings that need to be threaded on to the outlet. It is just there to keep tubing from sliding off discharge when pump is plugged in.