Filter media sand should be sized so that the grains are between which of the following diameters?

The correct choice identifies the optimal size range for filter media sand, which plays a crucial role in the efficiency of water filtration systems. Sand used in filters is essential for removing impurities and ensuring that the filtered water meets quality standards.

A grain size of 0.3 to 0.6 millimeters strikes an appropriate balance between effective filtration and flow rate. Grains within this range provide sufficient surface area for capturing and retaining particles while allowing an adequate velocity of water to pass through the filter media. This ensures that the filter operates effectively without clogging too quickly, which can happen if the grains are either too small or too large.

Particles that are smaller than this range may lead to excessive clogging, requiring more frequent backwashing and maintenance. Conversely, grains that are too large may result in insufficient filtration, failing to capture smaller contaminants effectively. Therefore, utilizing sand sizes between 0.3 and 0.6 millimeters represents the standard practice for achieving an efficient filtration process in water treatment operations.