Abstract: A bi-folding spa cover and lift for installing and removing the spa cover are disclosed. The cover includes a pair of cover members which each cover about one-half of the spa. Each cover member consists of a pair of structural plastic panels pivotably secured together so that the cover members can outwardly fold in opposite directions. A flat bottom surface of the panels rests on and overlaps a rim of the spa. A flat rubber gasket secured to the bottom of the panels engages the rim and seals the spa cover to the spa. The lift includes a pair of lift assemblies, each connected to an associated one of the cover members. Each lift assembly includes a pair of vertically extending and horizontally spaced-apart rails positioned beside the spa, a pair of blocks each linearly movable along the rails, and a pair of hinges each secured between an associated one of the blocks and the associated one of the cover members.

Abstract: An ionizer for treating swimming pool water including an enclosure and an electrode housing. The electrode housing is removably secured to a wall of the enclosure and integrally includes a mounting bracket, a hollow cylindrical body, a sensor well, and a projection. The projection sealingly receives a pair of ion-producing electrodes. A vibration sensor is attached to an interior surface of the housing, and is operable to sense when water is flowing through the electrode housing. A method for determining and indicating when the electrodes need replacement is also disclosed.