Problem to be solved: to provide a filter block and a water purifying apparatus for use in an ornamental fish tank, in which a plurality of filter bodies used as an outer hanging type of a water tank are assembled in a simple type as a water purifier of the lower type type and the damage is not impaired.Solution: a lower cover 24 is provided which can be arranged in such a way that a plurality of filter bodies are used as the outer tank type. In the lower cover 24 with the upper end opened, a plurality of filter bodies 20 (not shown in the figure are not limited to three) are accommodated in a state in which each of the opening portions 200B and 200C is oriented upward and arranged in the direction of increasing the thickness.Selection diagram【課題】水槽外掛けタイプとして用いられる濾過器本体を複数連ねて下置きタイプの浄水装置として簡単に組み立てられ、美観も損ねない、観賞魚水槽に用いられる濾過ブロック，浄水装置を提供する。【解決手段】水槽外掛けタイプとして用いられる濾過器本体を複数個立てて並べて収容可能な下部カバー２４を設ける。上端が開口された下部カバー２４の中に、複数個（図示の例では３個であるが３個に限定されない）の濾過器本体２０が、それぞれの開口部２００ｂ，２００ｃを上に向けて立てて、厚みを増やす方向に並べた状態で、まとめて収容されている。【選択図】図１５
