Which parameter is commonly monitored to decide when to backwash a filter?

Which parameter is commonly monitored to decide when to backwash a filter?

• A. Headloss
• B. Temperature
• C. Color
• D. Taste

Answer: (A)

Backwashing is triggered by how clogged the filter bed has become. The key indicator is headloss—the pressure difference across the filter. As solids accumulate in the bed, hydraulic resistance increases and the pressure on the upstream side rises relative to the downstream side. When headloss reaches a set limit, backwashing is started to lift and re-expand the media and flush out the trapped material, restoring filtration efficiency. Temperature, color, and taste don’t reliably show how much the filter is loading or its hydraulic condition; they reflect other water quality factors rather than the filter’s current capacity to function properly.

Backwashing is triggered by how clogged the filter bed has become. The key indicator is headloss—the pressure difference across the filter. As solids accumulate in the bed, hydraulic resistance increases and the pressure on the upstream side rises relative to the downstream side. When headloss reaches a set limit, backwashing is started to lift and re-expand the media and flush out the trapped material, restoring filtration efficiency. Temperature, color, and taste don’t reliably show how much the filter is loading or its hydraulic condition; they reflect other water quality factors rather than the filter’s current capacity to function properly.