| 摘要 |
PROBLEM TO BE SOLVED: To provide a cultivation water tank excellent in convenience and suppressed of risk causing water leakage.SOLUTION: A plurality of resin foam boards are formed into rectangular shapes, and are used as follows that: they are horizontally and vertically arranged with their side edge parts in contact with one another; and are covered with a waterproof sheet in a condition where they are arranged to form at least a bottom board part of a cultivation water tank for hydroponic cultivation. A first side edge projecting part projecting outward in a planar direction is formed at the first side edge part in four side edge parts so as to be connected with one another when arranging the boards, and a second side edge recessed part engageable with the first side edge projecting part is formed at the second side edge part facing the side edge part. |
