Backwashing
Backwashing is the process of reversing water flow through a sand or DE filter to flush accumulated debris out of the filter media to waste.
Definition
Backwashing is the process of reversing water flow through a sand or DE filter to flush accumulated debris out of the filter media to waste.
Typical Values: Backwash when filter pressure is 8–10 psi above clean baseline
In Plain Language
In a sand filter, backwashing is initiated by turning the multiport valve to the backwash position, which reverses water flow through the filter, dislodging and flushing captured particles out through a waste line. The backwash cycle continues until the sight glass (if present) runs clear, typically 2–3 minutes. After backwashing, run the filter on the rinse setting for 30 seconds before returning to normal operation.
Why It Matters
Backwashing restores filter flow rate and filtration efficiency. Delaying backwashing beyond the 8–10 psi threshold reduces water quality.
Typical Values
Backwash when filter pressure is 8–10 psi above clean baseline
Last reviewed: 2026-06-01