Abstract: Water filters which comprise a multitude of discrete filter media elements in a chamber require periodic cleaning. However, the elements tend to become adhered to one another and to the interior surface of the chamber. The invention provides a water filter for use with ponds, comprising a filter chamber for containing filter media, and a first movable cutting member provided substantially immediately adjacent the interior wall of the chamber for movement across the surface of the interior surface of the wall to break the adherence of filter media to the interior wall.

Abstract: Water filters which comprise a multitude of discrete filter media elements in a chamber require periodic cleaning. However, the elements tend to become adhered to one another and to the interior surface of the chamber. The invention provides a water filter for use with ponds, comprising a filter chamber for containing filter media, and a first movable cutting member provided substantially immediately adjacent the interior wall of the chamber for movement across the surface of the interior surface of the wall to break the adherence of filter media to the interior wall.

Abstract: Water filters require filter media which may be a substantially single structure such as open-cell foam, or comprised of a plurality of relatively small elements. The present invention provides composite mechanical water filter media for use in mechanical water filters comprising a plurality of first elements having a first shape and a plurality of second elements having a second shape, the first and second shapes being substantially different from one another, the elements being arranged to interlock with one another.

Abstract: Dosing chambers, for use with pressurised water filters of the type used with ponds, require isolation before accessing to prevent water egress. The invention comprises a chamber in which dosing substances may be placed, a water inlet and a water outlet, a lid for sealingly closing the chamber, a valve for closing the water inlet and an interlock means for operating the valve to close the water inlet as the lid is removed, so that when dosing substances are placed into the chamber pressurised water is prevented from issuing through the inlet.

Abstract: A submersible electric aquarium heater includes an open-ended glass tube enclosing an electric resistance heater carried by an axially disposed former. First and second bungs seal the ends of the tube. A printed circuit board carrying an adjustable electronic thermostat is positioned in the tube by first and second locators each including an annular spacer engageable with the tube and a centering post. The centering post of the first locator is insertable within the first bung, while that of the other is fixedly inserted into an end for the axially disposed former. The temperature setting of the thermostat is adjusted by a device mounted for rotation in the tube by the first bung and first locator and including a drum provided with indicia visible through the tube wall to indicate the set temperature.