# After the second filling, when the water level falls below 27.5 cm, add enough water to bring the depth of water to 30 cm or slightly more. Note that these measurements are from the base of the soil bottom (using the installed marker), not the gravel layer. | # After the second filling, when the water level falls below 27.5 cm, add enough water to bring the depth of water to 30 cm or slightly more. Note that these measurements are from the base of the soil bottom (using the installed marker), not the gravel layer. |