It is important to set up the plumbing properly with the EXT pumps. Improper plumbing setups can lead to failure or damage to the pump. We recommend an Aquascape EXT Pump Plumbing Kit. The EXT Pump Plumbing Kit provides all the necessary fittings and valves to make the EXT pump easy to install, prime, and operate. Once primed, the pump can be turned on and off without priming if water remains in the suction line. 3″ swing check valve located in the Pondless® Waterfall Vault provides pump suction intake to supply water to the EXT pump 3″ union connection makes maintenance quick and easy 3″ liner flange allows the plumbing to penetrate through the liner sub-surface making it easier to disguise the plumbing transitioning outside the edge of the pond 3″ van stone flange connection on the pump intake and a 2″ van stone flange connection on the pump discharge make it easy to service the pump 2″ priming port and ball valve included to make initial starting simple 2″ to 3″ bushing provides underground connection to 3″ Aquascape Flexible PVC pipe All PVC pipe sold separately