| 摘要 |
PURPOSE:To permit the subject device to be maintained easily and a comfortable environment to be produced for a live fish by providing a first filter tank for removing rough solids such as waste matter from the fish and dirt and a second and a third filter tank for increasing the amt. of oxygen dissolved and removing rough org. matter and bacteria. CONSTITUTION:The subject device consists of a first filter tank 1 having therein separators 7 and filter materials 6 stacked alternately in a number of tiers, a second filter tank 2 having a void ratio of 10-900% based on the total space of the tank and a third filter tank 3 made up of the combination of the porous bodies 17 capable of supporting thereon physiologically active substances and the containers 15 having an open end arranged in a number of tiers. Water is treated in the filter tanks 1-3 in that order. Since, in this way, there is no occurrence of an alga or the like, the device is easily maintained and, due to the presence of a large amt. of the oxygen dissolved in the water despite the disuse of an air pump, fish can live comfortably in a tank, free from stress build-up. |
