What backwashing does
Backwashing reverses water flow through a filter so trapped debris is carried to waste. It is commonly associated with sand and many diatomaceous earth filter systems. The exact valve sequence, pump procedure, duration, and media-restoration steps depend on the equipment.
What filter cleaning means
Cleaning may involve opening the filter, removing cartridges or grids, rinsing components, inspecting seals, and using an approved cleaning process. Cartridge filters are generally cleaned rather than backwashed. Sand and DE systems also need periodic inspection and deeper service beyond routine backwashing.
Use your clean-pressure baseline
Record the gauge pressure when the filter is clean, baskets are clear, valves are in their ordinary positions, the water level is correct, and the system is flowing normally. A gradual pressure rise from that baseline can indicate accumulating restriction, but the manufacturer’s recommended threshold should guide service.
Pressure is not the only signal
Also watch return flow, skimming action, cleaner behavior, visible air, water clarity, leaks, and changes after valve adjustments. Low pressure may point to a suction-side restriction or low water level rather than a dirty filter. A sudden pressure change deserves investigation before routine cleaning.
Keep a service record
Write down the date, clean baseline PSI, pressure before service, procedure performed, and pressure afterward. Over time, the record helps show whether filter cycles are shortening and whether another flow or water-quality issue may be present.