A hydraulic valve engages a through opening delimited through a bottom wall of a tank for a liquid and comprises a cage element connected inside the bottom wall, a shutter movably housed in the cage element, a hollow connection element which hermetically engages the through opening delimiting a passage that passes through the hydraulic valve, wherein the hollow connecting element comprises an engagement portion which extends into the through opening and defines a passage opening selectively occludable by means of a shutter as a function of the quantity of liquid in the tank, wherein the hollow connecting element comprises radial notches which define respective passages for a liquid sucked out of the tank through which the formation of a vortex is prevented and the sucking in air.

A method for treating water in a spa or a hot tub includes, for example, suspending a water treatment dispenser from an upper end of a filter cartridge disposed in a skimmer of the spa or the hot tub. The dispenser includes a water treatment material. A supply of water is passed from the spa or the hot tub into the skimmer and through the filter cartridge so that the dispenser suspended in the filtered water in the filter cartridge is operable to dispense the water treatment material from the dispenser, and a supply of treated filtered water from the filter cartridge is returned to the spa or the hot tub. A cover, for example, may be employed when the dispenser is not used.

A spa includes a shell having at least one cavity, the spa shell being configured to hold a volume of water, at seat insert having a plurality of hydrotherapy jets, the seat insert being received in the at least one cavity and defining a space between the seat insert and the shell, and a drain associated with the at least one cavity for removing water from the space between the seat insert and the shell.

A drain assembly includes an outer housing and an inner housing. The outer housing includes a base and a first plurality of sidewalls extending from the base. The inner housing is configured for connection with the outer housing and includes a second plurality of sidewalls, a center hub disposed inward relative to the second plurality of sidewalls, and a plurality of inner portions connected to the second plurality of sidewalls and the center hub. In an assembled configuration, the inner housing is connected with the outer housing such that (i) the inner portions and portions of the base define a plurality of fluid conduits and (ii) the second plurality of sidewalls are offset from the first plurality of sidewalls defining a void, the fluid conduits are arranged in a vortex-shaped configuration, and the void is in fluid communication with the fluid conduits and the center hub.

A docking station for a self-propelled pool cleaner may be supported at one or more locations within a swimming pool or spa, such as but not limited to a skimmer of the swimming pool or spa, a port for a circulation system of the pool or spa such as an inlet or an outlet, a pool light fitting of the pool or spa, and/or on a floor of the pool or spa. The docking stations may utilize existing features of the swimming pool or spa without requiring additional devices or systems for installing the docking station.

A drain valve comprises a valve shell and a valve core which comprises an inner core and an outer core. In the process of draining and closing, the outer core and the inner core of the valve is rotated through operating the handle nut and a rotating part, so as to realize the accurate control of the position of the valve core. When draining water, the first through hole and the second through hole are aligned, and then water is drained to the water outlet pipe through the outlet of the valve core, so that the drainage is smooth; when closed, the valve core is completely pushed into the interior, and the internal water is squeezed out, thus reducing the possibility of residual water, effectively preventing the drain valve from being frozen, and ensuring the normal use of the drain valve in cold climates.

An overflow system for a recreational pool includes a drain configured to be mounted to a bottom of the recreational pool, and a drain pipe configured to extend substantially horizontally from the drain under a perimeter wall defining a boundary of the recreational pool to outside the boundary. The system also includes a standpipe configured to be positioned outside the boundary and having a first end and an open second end. The first end is coupled to the drain pipe and the second open end has an overflow elevation between a normal water level elevation for the recreational pool and a top of wall elevation of the perimeter wall. In addition, the system includes a recirculation pipe having a first end in fluid communication with the recreational pool and a second end in fluid communication with the standpipe proximate the second open end.