The edge of the stones on the right of the tank also roughly aligns with line 4.
[Fig 2]: Here we can see the plant growth of the Dwarf Hair Grass lies right along line 2. Line 3 follows along the edge of the hardscape design. The edge of the stones on the right of the tank also roughly aligns with line 4. At the intersection of lines 1 and 3, there is a small cave created with the placement of the stones.