| 摘要 |
Bottom sand for growing aquatic plants containing a granular sinter consisting essentially of volcanic ash and having a bonding strength to collapse when a pressure of 2.5 kg/cm2 or above is applied on a 1.0 cm thick layer. This bottom sand permits good filtration of water and satisfactory growing of aquatic plants. Aquariums using such bottom sand purifies the water contained in it and assures satisfactory growth of aquatic plants placed in it. |
