Drip Irrigation Index
All irrigation guides

How to choose a drip irrigation filter

Start with the emitter manufacturer’s filtration requirement and the quality of the water. Then size the filter for the zone’s flow and the pressure loss you can afford.

Filtration ratings from three published tape examples

Toro EAxxx1222
140 mesh (105 microns).
Rivulis 508-12-220
150 mesh.
Rivulis 508-12-340
120 mesh.

Use the exact model’s filtration rating

Check the required opening size, preferably in microns when both manufacturers publish it. Mesh counts alone can vary with how the screen is built. The examples above show why the exact tape model matters, even within one manufacturer’s range.

If one filter feeds several emitter models, account for the finest filtration required by those models. Confirm the filter’s rating in its own documentation and keep enough pressure for the regulator and laterals.

Match the filter to what is in the water

A screen filter can catch suspended particles in relatively clean water. A supply with algae or heavy organic material may require media filtration or a treatment arrangement sized for that source. Inspect or test well and surface water before selecting a filter.

A finer screen does not solve every clog. Mineral deposits and biological growth have different causes. For persistent clogging, look at what collects in the filter and get a water analysis before choosing treatment.

Check the pressure drop with clean and dirty filters

Record the pressure difference across the clean filter with a normal zone running. Compare it with the manufacturer’s rated loss and cleaning instructions. An increasing difference at the same flow indicates the filter needs attention.

Clean the filter on the schedule indicated by its pressure loss and the maker’s instructions. Flush the line ends after work that might send debris into the laterals.

Look up the specifications for your drip tape or calculate flow for your rows.

Sources