PROBLEM TO BE SOLVED: To provide a water tank cleaning device which can quickly and smoothly remove dirt accumulated on a bottom in a water tank in which aquarium fishes such as goldfish and tropical fish are reared.SOLUTION: A water tank cleaning device comprises on a water absorption hole 3, a water absorption valve mechanism 10 having a water absorption valve body 9 which can be opened and closed and which can allow flow of water W in only one direction to a pump chamber 2 side from a water absorption body 8 side. A water discharge body 11 is provided on a discharge hole 4, and on the water discharge hole, a water discharge valve mechanism 13 having a water discharge valve body 12 which can be opened and closed and which allows flow of water in only one direction from a pump chamber side to the water discharge body side, is provided. A filter member 14 is detachably provided on the water discharge body, and on the water discharge body, regulation parts 15, 16 for regulating opening limit of the water absorption valve body and the water discharge valve body are provided.SELECTED DRAWING: Figure 6COPYRIGHT: (C)2020,JPO&INPIT【課題】金魚、熱帯魚等の観賞魚を飼育する水槽内の底に溜まった汚物等を円滑にかつ迅速に行える水槽清掃具の提供。【解決手段】吸水口３に吸水体８側からポンプ室２側への一方向のみの水Ｗの流れを可能とする開閉動作自在な吸水弁体９をもつ吸水弁機構１０が配設され、吐水口４に吐水体１１が配設され、吐水口にポンプ室側から吐水体側への一方向のみの水の流れを可能とする開閉動作自在な吐水弁体１２をもつ吐水弁機構１３が配設され、吐水体にフィルタ部材１４が着脱自在に配設されてなり、吸水弁体及び吐水弁体の開限度を規制する規制部１５・１６を配設してなる。【選択図】図６
