Abstract: Strong acid cation resins used alone or in combination with zeolite-based ion exchange resins are encapsulated in various water permeable polymer fabric bags of various geometries and thicknesses to reduce the calcium hardness levels during swimming pool and spa water fills. The resin bags are strategically placed in the pool or spa to allow water under pressure to flow through the ion exchange media to exchange calcium or magnesium ions with sodium or other harmless cations.

Abstract: A filter element for positioning in a filter compartment of a spa includes a plastic mesh outer cylinder and a plastic mesh inner cylinder, the inner cylinder being positioned coaxially with respect to the outer cylinder to define an annular interior chamber with a filter element of annular cross-section disposed in the chamber and having keyed landings formed on the top and bottom thereof, which respectively mate and interlock with one or more keyed landings on top and bottom caps of the filter element. The apparatus may further include a plurality of vertically disposed mesh compartments interlinked in a ring and disposed within the filter element, the compartments being filled with a selected filter medium or filter media.

Abstract: A filter element for a pool or spa including a sintered plastic outer cylinder of a first diameter, a sintered plastic inner cylinder of a second diameter less than said first diameter; the inner cylinder being position coaxially with respect to the outer cylinder to define an annular interior chamber; and a selected granulated filter medium or combination of media residing in the annular interior chamber.

Abstract: An oxidizer generating apparatus comprising a cylindrical housing and an electrode assembly attached at one end of the housing comprising at least three vertically disposed electrodes, the electrodes being spaced apart so as to define a water flow path between them, the electrodes comprising titanium outer electrodes and at least one inner diamond electrode

Abstract: A method of sanitizing water contained in a spa is provided which comprises installing a chlorine generating cell including a diamond electrode in a filter compartment of the spa, employing a resin-filled calcium remover bag to reduce the hardness of the water, adding salt to the water; and operating the chlorine generating cell to generate chlorine and other sanitizing agents for sanitizing the water.

Abstract: An oxidizer generating apparatus comprising a cylindrical housing and an electrode assembly attached at one end of the housing comprising at least three vertically disposed electrodes, the electrodes being spaced apart so as to define a water flow path between them, the electrodes comprising titanium outer electrodes and at least one inner diamond electrode.

Abstract: An oxidizer generating apparatus having a housing with a fluid inlet at a first end, the inlet leading to a chamber, and a lid attachable to a second end of the housing for closing the chamber. First and second pairs of electrodes are attached to the lid so as to suspend them within the chamber in position to generate chlorine and/or other oxidants from fluid pumped through the housing.

Abstract: A spa sanitizing apparatus including a sanitizing agent generating cell, an H-Bridge circuit arranged to supply a voltage to electrodes of the cell, a controller circuit for controlling the operation of the H-Bridge circuit, and a watch dog circuit for monitoring a voltage applied to the electrodes and for shutting down power if the voltage departs from a pre-determined limit.

Abstract: A method of sanitizing water contained in a spa is provided which comprises installing a chlorine generating cell including a diamond electrode in a filter compartment of the spa, employing a resin-filled calcium remover bag to reduce the hardness of the water, adding salt to the water; and operating the chlorine generating cell to generate chlorine and other sanitizing agents for sanitizing the water.

Abstract: A filter element for positioning in a filter compartment of a spa includes a plastic mesh outer cylinder and a plastic mesh inner cylinder, the inner cylinder being positioned coaxially with respect to the outer cylinder to define an annular interior chamber with a filter element of annular cross-section disposed in the chamber and having keyed landings formed on the top and bottom thereof, which respectively mate and interlock with one or more keyed landings on top and bottom caps of the filter element. The apparatus may further include a plurality of vertically disposed mesh compartments interlinked in a ring and disposed within the filter element, the compartments being filled with a selected filter medium or filter media.

Abstract: A filter element for a pool or spa including a sintered plastic outer cylinder of a first diameter, a sintered plastic inner cylinder of a second diameter less than said first diameter; the inner cylinder being position coaxially with respect to the outer cylinder to define an annular interior chamber; and a selected granulated filter medium or combination of media residing in the annular interior chamber.

Abstract: A filter element for a pool or spa including a sintered plastic outer cylinder of a first diameter, a sintered plastic inner cylinder of a second diameter less than said first diameter; the inner cylinder being position coaxially with respect to the outer cylinder to define an annular interior chamber; and a selected granulated filter medium or combination of media residing in the annular interior chamber.

Abstract: An oxidizer generating apparatus comprising a cylindrical housing and an electrode assembly attached at one end of the housing comprising at least three vertically disposed electrodes, the electrodes being spaced apart so as to define a water flow path between them, the electrodes comprising titanium outer electrodes and at least one inner diamond electrode

Abstract: Strong acid cation resins used alone or in combination with zeolite-based ion exchange resins are encapsulated in various water permeable polymer fabric bags of various geometries and thicknesses to reduce the calcium hardness levels during swimming pool and spa water fills. The resin bags are strategically placed in the pool or spa to allow water under pressure to flow through the ion exchange media to exchange calcium or magnesium ions with sodium or other harmless cations.

Abstract: An oxidizer generating apparatus having a housing with a fluid inlet at a first end, the inlet leading to a chamber, and a lid attachable to a second end of the housing for closing the chamber. First and second pairs of electrodes are attached to the lid so as to suspend them within the chamber in position to generate chlorine and/or other oxidants from fluid pumped through the housing.

Abstract: A high-density filtration module for separating a liquid from a high viscosity and/or high solids feed comprising sheets of porous filtration membrane being disposed generally concentrically about a central porous tube. The membranes are separated by a sheet of feed liquid spacer material having two sets of generally parallel ribs of similar size regularly spaced apart from one another which project from opposite surfaces of a thin central layer. Permeate carrier layers are disposed adjacent discharge surfaces of the sheet membranes. The sets of ribs are arranged so that each rib is located substantially equidistant from the two adjacent ribs in the opposite set, and the central layer is about 40% or less as thick as the base of a rib where it joins the central layer.