Drip Filter Sizing & Keep Emitters Clear
Sizes filter area
Enter your system flow, the filter's rated flow per m² and the emitter size to get the filter area you need and the right mesh number in microns — so emitters don't clog and pressure stays up.
Size your drip filter
Next: pick a screen/disc filter offering at least 0.2 m² of filtration area at 115 mesh (130 µm) for this flow.
Rated capacity per m² varies by filter type (screen, disc, sand) and water quality; under-sizing raises head loss and clogs emitters faster.
Drip filter sizing — key facts
- Filter area
- system flow ÷ rated flow per m²
- Mesh ↔ micron
- micron ≈ 15000 ÷ mesh
- Match to emitter
- mesh fine enough for the passage
- 120 mesh
- ≈ 125 microns
- 150 mesh
- ≈ 100 microns
- Undersized filter
- clogs & loses pressure
- Types
- screen · disc · media
- Privacy
- Runs in your browser; nothing uploaded
The filter is the heart of a drip system
Drip emitters live or die by their water. Their tiny passages clog on sand, silt, algae and debris, so every drip system must filter the water first. Two numbers decide whether your filter does the job: the area, which must be big enough to pass the whole system flow without choking, and the mesh, which must be fine enough to catch anything that would block your emitters. Get either wrong and you face uneven watering, pressure loss and endless cleaning.
This tool sizes both at once: the filter area = system flow ÷ the filter's rated flow per m², and the mesh number (≈ 15000 ÷ micron) matched to your emitter. Use it to choose a filter body that won't clog or starve the field. Pair it with the Drip System Flow, Chlorination and Flushing tools to keep the whole system running clean.
Stop emitters clogging
Mesh fine enough for your emitter passage.
Hold the pressure
Enough area to pass full flow without choking.
Mesh to microns
Convert mesh and micron the easy way.
Pick the right body
Size the filter to your system flow first.
Frequently Asked Questions
Why does a drip system need a filter?+
Drip emitters have tiny openings that clog easily on sand, silt, algae and organic debris carried in the water. A filter removes those particles before they reach the laterals. Without adequate filtration, emitters block, application becomes uneven, and parts of the field are starved while pressure builds elsewhere — so the filter is the heart of a reliable drip system.
How is the required filter area calculated?+
Filter area = system flow ÷ the filter's rated flow per square metre. The manufacturer states how much water the filter element can pass per m² of screen or disc; dividing your total system flow by that figure gives the screen area you must install. The tool does this so you can pick a filter body that is big enough.
What mesh number should I choose?+
Match the mesh to the emitter: the openings must be several times smaller than the emitter passage. A common rule of thumb converts mesh to microns as roughly 15000 ÷ micron, so a 120-mesh screen is about 125 microns. The finer the emitter, the higher the mesh number you need. The tool suggests the mesh from your emitter size.
What is the relationship between mesh and microns?+
Mesh counts the openings per linear inch, while microns measure the opening size. As mesh number rises, the openings get smaller, so the two move inversely — approximately microns ≈ 15000 ÷ mesh. A 150-mesh screen is about 100 microns. Filter makers usually print both numbers; the tool converts between them for you.
What happens if the filter is undersized?+
An undersized filter clogs quickly, causing a large pressure drop across it. That starves the laterals, makes emitter discharge uneven, and forces frequent cleaning or backflushing. Sizing the filter area generously to your system flow keeps the pressure loss low and the cleaning interval long, protecting both uniformity and pump energy.
Screen, disc or media filter — which do I need?+
Screen filters suit clean groundwater with inorganic sediment; disc filters handle a mix of organic and inorganic load and hold more dirt; sand/media filters are best for heavy algae and organic matter from open ponds and canals. Sizing by area and mesh applies to all; choose the type by your water source and quality.
How often should I clean or backflush the filter?+
Watch the pressure drop across the filter — when it rises by a set amount (often a few metres of head), it's time to clean or backflush. Properly sized filters need cleaning less often. Automatic backflush controllers trigger on pressure differential or a timer, keeping the system running without constant manual attention.
Does filtration replace flushing the laterals?+
No — filtration stops particles entering the system, but fines that pass through still settle at the lateral ends, and biological growth can form inside the lines. You still need periodic lateral flushing and, where needed, chlorination to keep emitters clear. See the Drip Flushing and Drip Chlorination tools for those routines.
Can I use this for any drip system?+
Yes — the logic (filter area = flow ÷ rated flow per m², mesh = 15000 ÷ micron matched to the emitter) applies to surface and subsurface drip of any size. Enter your system flow and emitter size to get the area and mesh, then choose a filter body and type to match your water source.