How to choose a filter for an irrigation system
Disc, screen, or sand? Which mesh and diameter? Breaking down filter selection by water source and equipment type.
Why the filter is a critical component
Emitters have outlet openings of 0.2–1.5 mm. Even a tiny grain of sand or iron deposit clogs an emitter permanently. One clogged row = uneven irrigation = yield loss.
Fact: 80% of drip system failures are caused by an incorrectly chosen or missing filter. Replacing 1 ha of clogged drip tape costs UAH 15,000–25,000. A filter costs UAH 500–3,000.
What mesh means and how to choose it
Mesh is the number of openings per 1 inch (25.4 mm) of filter screen. The higher the mesh, the smaller the particle that passes through. For drip irrigation, the standard is 120–150 mesh (100–125 µm).
| Mesh | Particle size | Application |
|---|---|---|
| 40 mesh | 420 мкм (0.42 мм) | Impulse sprinklers, large rotors |
| 80 mesh | 180 мкм | Spray heads, small rotors |
| 120 mesh | 125 мкм | Drip tape 1.6–2.0 L/h, MP Rotator |
| 150 mesh | 106 мкм | Drip tape 0.8–1.3 L/h, PC emitters |
| 200 mesh | 75 мкм | Micro-irrigation, subsurface drip (SDI) |
Three filter types
Screen filter
A cylindrical stainless steel or polyethylene screen. The simplest and cheapest type.
Pros:
- Affordable: UAH 200–800
- Easy to clean — remove the screen, rinse with water
- Transparent housing — contamination is visible
Cons:
- Poor performance with organics (algae, biofilm) — clogs quickly
- Small effective filtration area
- Not suitable for well water with iron (Fe > 0.5 mg/L)
Best for: Clean municipal water, home gardens, small systems up to 1,000 L/h.
Disc filter
A stack of plastic discs with radial grooves. Filtration occurs between the discs — a larger 3D surface area than a screen. The standard for drip irrigation.
Pros:
- Large filtration area — throughput 3–5× higher than a screen filter of the same size
- Effectively captures organics: algae, biofilm
- Durable: 5–10 years with proper care
- Models with backflush available (Amiad, Arkal, Azud)
Cons:
- More expensive: UAH 800–3,000 for residential models, UAH 5,000–25,000 for commercial
- Cleaning: disassemble the stack, rinse each disc — 5–10 min
- Not for water with high sand content — grains get stuck between discs
Best for: Drip irrigation for farm systems, greenhouses, well water with organics. The professional system standard.
Sand filter (sand/media filter)
A large tank filled with a layer of quartz sand or glass beads. Filtration occurs through a 500–800 mm layer of granules. For heavily contaminated water.
Pros:
- Enormous dirt-holding capacity — captures 5–10× more contaminants than a disc filter
- Automatic backflush — valve switching
- The only option for pond, river, or open reservoir water
- Removes suspended particles and partially iron (through oxidation)
Cons:
- Expensive: from UAH 15,000
- Bulky: 0.5–1.2 m diameter, 1.2–2 m height
- Pressure loss across the filter — 0.3–0.8 bar
- Requires a large water tank for backflush (100+ L)
Best for: Ponds, rivers, open reservoirs. Large-scale farm systems from 2 ha. Often paired with a disc filter: sand → 120 mesh disc.
Selection by water source
- Municipal supply: screen or disc filter, 120 mesh, 1/2"–3/4"
- Clean well (Fe < 0.3, TDS < 500): disc filter, 120–150 mesh
- Well with iron (Fe 0.3–3 mg/L): aerator + settling tank + 150 mesh disc filter, periodic citric acid treatment
- Well with sand: hydrocyclone (centrifuge) + 120 mesh disc filter
- Pond / river / rainwater reservoir: sand filter + 150 mesh disc filter + chlorination for algae
Maintenance — the key to longevity
- Pressure differential monitoring: install a gauge before and after the filter. When the differential exceeds 0.5 bar, it's time to clean
- Home system: clean once every 1–2 weeks during the season. Commercial: 1–2 times per day at peak irrigation
- Limescale buildup: 3–5% citric acid solution (30–50 g/L) for 1–2 hours. NOT 1 tablespoon per 10 L — that concentration is too weak
- Disc/screen replacement: once every 3–5 years or when visibly damaged
- Winter storage: drain water, blow out with a compressor, remove and store indoors in a warm space
For farms and greenhouses
In commercial systems, filtration is a separate engineering node, not a single filter:
- Multi-stage filtration: hydrocyclone (sand) → sand filter (organics) → disc filter (fine minerals) → fertigation
- Backflush controllers: automatic flushing by pressure or timer (Amiad Filtomat, Azud Helix Automatic, Arkal Spin Klin)
- Water analysis BEFORE selecting filtration: TDS, Fe, Mn, turbidity, pH, bacteria. Without a lab report, selection is guesswork
- Periodic chlorination or HCl injection — against biofilm in pipelines (shock chlorination at 5–10 ppm for 1 hour once a month)
- ISO 9912-1/-2/-3 — standards for irrigation system filter specifications. Reference is required for tenders
Ready to choose a filter?
Our catalog offers screen, disc, and commercial backflush filters from UAH 200 to complete sand filtration stations.