Abstract: A tank drain assembly for swimming pool filters is provided characterized by an improved locking and orienting structure individually locking collector tubes into their respective sockets in the manifold surrounding the common drain port of the filter tank, each such structure comprising spring finger means segmentally formed on the socket end of the tubes, and a finger receiving recess within the tube socket sized and located to operatively orient the tube apertures responsive to receiving the finger means in tube locking relation.

Abstract: A valve is provided adapted to multiple modes of use including filter, backwash, rinse, recirculate, and direct to waste, on a swimming pool filter of the type normally filtering water under pressure through a backwash-regenerable filtering medium disposed in a filter tank. The valve comprises closely interfitting, relatively rotatable inner and outer sections having coaxially tapered annular walls defining interiorly open spaces respectively within the sections; the outer section wall has formed therein circularly spaced outer ports including an inlet port, a first outlet port, and a second outlet port. The inner section is normally seated against the outer section wall, its interior space being adapted to define a continuation of the filter tank in continuously hydraulically filled relation against unseating pressure imbalances across the inner section.

Abstract: A pool cover having solar energy heating capability is provided comprising sheet material adapted to furl about a reelless locus in a storage position and to be deployed in an extended position. The cover includes means continuously resiliently urging the sheet material into its furled position for storage, and means selectively overcoming and resisting said urging, comprising inflatable structure selectively inflated in sheet material deploying relation. The cover includes a wall portion responsive to solar energy to transfer heat to water, such as pool water, in contact therewith.