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: 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.