To provide an aquarium water circulation desalination filter device capable of preventing deterioration of water quality caused by accumulation of salts as a final product, in a household ornamental aquarium.SOLUTION: In a household ornamental aquarium, an illumination light source 1 and a reflector plate are provided in a filter tank of a circulation filter device for aquarium water, and covered with a shading wall part so that a photosynthetic organism can be raised in the filter tank, and salts are absorbed by the photosynthetic organism, to thereby clean the water quality of the aquarium water.SELECTED DRAWING: Figure 1【課題】家庭用観賞用の水槽に、最終生成物として塩類が蓄積し、水質が悪化することを防ぐ水槽水循環脱塩濾過装置を提供する。【解決手段】家庭用観賞用水槽において、水槽水の循環濾過装置の濾過槽に照明光源１と反射板を設け、遮光性壁部で覆って、濾過槽内に光合成生物を育成できるようにし、光合成生物に塩類を吸収させて、水槽水の水質を浄化する。【選択図】図１
