Which statement about filter media is true?

Which statement about filter media is true?

• A. Media size, type, and layering affect particle capture, head loss, and backwash requirements.
• B. Media has no impact on filtration efficiency.
• C. Only media color matters.
• D. Media should always be the same size throughout.

Answer: (A)

Filter media size, type, and how they are layered determine the pore structure the water passes through, which directly affects what particles get trapped and how easily water can flow. A bed with a mix of media sizes and a deliberate layering creates a gradation of pore spaces that improves particle capture, helps prevent channels from forming, and supports more consistent filtration performance. Different media materials have unique densities and surface properties, so they influence filtration efficiency and how much resistance (head loss) the water experiences as the bed collects solids. When solids accumulate, head loss rises and backwashing is needed to restore porosity and remove trapped material; the amount and frequency of backwash depend on the media chosen and how the bed is arranged. Media color does not change filtration performance, and having the same size throughout the bed removes the beneficial gradation that enhances capture and can lead to poorer filtration. The statement about size, type, and layering affecting particle capture, head loss, and backwash requirements is the best answer because it captures how these physical properties work together to drive filtration effectiveness.

Filter media size, type, and how they are layered determine the pore structure the water passes through, which directly affects what particles get trapped and how easily water can flow. A bed with a mix of media sizes and a deliberate layering creates a gradation of pore spaces that improves particle capture, helps prevent channels from forming, and supports more consistent filtration performance. Different media materials have unique densities and surface properties, so they influence filtration efficiency and how much resistance (head loss) the water experiences as the bed collects solids. When solids accumulate, head loss rises and backwashing is needed to restore porosity and remove trapped material; the amount and frequency of backwash depend on the media chosen and how the bed is arranged.

Media color does not change filtration performance, and having the same size throughout the bed removes the beneficial gradation that enhances capture and can lead to poorer filtration. The statement about size, type, and layering affecting particle capture, head loss, and backwash requirements is the best answer because it captures how these physical properties work together to drive filtration effectiveness.