Apparatus (42, 72) for filling a hose (36) with water (12) and simultaneously for expelling air from the hose while connected to the vacuum side of a pump (20) in preparation for cleaning debris from a swimming pool (10) without loss of the prime in the pump comprises a housing (44, 74) submergeable in the water and having a pair of chambers (46, 48 & 76, 78) respectively having inlets (58, 80) and outlets (64, 86), with the inlets being open to the water and the outlets being coupled respectively to the pump and to the hose. Impellers (54, 100 & 56, 102) respectively in their chambers are coupled together by a shaft (52, 98) in which a first of the impellers (54, 100) is driven by a second of the impellers (56, 102) when water is drawn by the pump past the second of the impellers. In one embodiment, elbow conduit (110) can be slid from a first position where water purges air from the hose to a second position where the hose is used to clean debris from the swimming pool. In another embodiment a hose end is first coupled to the pump's pressure side (24) to expel air from the hose and thereafter, without removing the hose end from the water, the hose end is coupled to the pump's vacuum side (22) to vacuum the pool.