Abstract: A pond filtration device for filtering impurities from pond water and a backflush system for cleaning the filtration device. The illustrated embodiment includes a watertight body with a filter cage mounted longitudinally therein. A filter medium, such as burlap, encloses the filter cage and uses impurities filtered from the pond water as a natural filter to further filter the pond water. After the filter is full of impurities, the backflush system cleans the filter and removes the impurities from the watertight body. The backflush system includes a backflush member threadably mounted to a rotatable screw shaft. The backflush member projects water radially through the filter cage and filter medium to clean impurities therefrom.

Abstract: A device for cleaning gravel and breaking up clusters of gravel in a fish pond comprises an integral body having a lower housing into which gravel is received and an upper housing which has an outlet for connection to a pump for drawing water and gravel into the integral body. The upper housing has a greater cross-sectional area than the lower housing so that the lower housing limits the size of gravel clusters entering the integral body from the pond bottom. A manifold encircles the lower housing of the integral body and has aligned perforations therein with the lower housing so that water introduced into the manifold radially and inwardly projects into the lower housing for breaking up the gravel clusters.

Abstract: Fish foods and food supplements are provided that comprise an amount of preserved immature insects, e.g., dried housefly or soldier fly larvae or pupae, effective to improve the growth, feeding efficiency, or coloration of fish, including, but not limited to, koi, trout, bass, catfish, and tropical aquarium fish. Also provided are related methods of improving the growth, feeding efficiency, or coloration of fish.