PROBLEM TO BE SOLVED: To provide an aquarium water tank which reduces generation of an alga in a fish culture water tank, eliminates labor of frequent cleaning in the tank, and is also an excellent interior.SOLUTION: The aquarium water tank includes, separately from a fish culture water tank 2, a dirty water treatment tank 3 including a shellfish culture tank 5 and a shellfish oviposition tank 7. A pump device 12 is arranged which circulates water between the fish culture water tank 2 and dirty water treatment tank 3. Dirty such as fish excrement and residual feed generated in the fish culture water tank 2 is transferred to the dirty water treatment tank 3 together with water flow and fed to shellfish S in the dirty water treatment tank 3, to be subjected to filter treatment. Water brought into a poor nutritional state after the filter treatment is circulated to the fish culture water tank 2.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】魚類飼育水槽内の藻の発生を低減し、水槽内の頻繁な清掃の手間を省き、インテリアとしても優れたアクアリウム水槽を提供する。【解決手段】魚類飼育水槽2とは別に、貝類飼育槽5と貝類産卵槽7を備えた汚水処理槽3を設ける。魚類飼育水槽2と汚水処理槽3との間で水を循環させるポンプ装置12を設ける。魚類飼育水槽2内で発生する魚類の排泄物及び残餌などの汚物を水流と共に汚水処理槽3に移行させ、汚水処理槽3内の貝類Sに汚物を給餌することで濾過処理し、濾過処理されて乏栄養状態となった水を魚類飼育水槽2に環流させる、【選択図】図1
