Calculator Inputs
Use the emitter method, or override with known peak flow.
Example Data Table
These examples show typical garden-scale scenarios and outputs.
| Scenario | Emitter setup | Design flow | Micron | Suggested inlet |
|---|---|---|---|---|
| Raised beds | 300 emitters @ 2.0 L/h, 1 zone | ~13.2 L/min | 150 µm | 3/4 in |
| Fruit trees | 120 emitters @ 4.0 L/h, 2 zones | ~21.1 L/min | 150 µm | 1 in |
| Drip tape row | 800 emitters @ 1.0 L/h, 1 zone | ~17.6 L/min | 120 µm | 1 in |
Formulas Used
- Zone flow (metric):
L/min = (Emitter L/h × Emitters) ÷ 60 - Zone flow (imperial):
gpm = (Emitter gph × Emitters) ÷ 60 - Total operating flow:
Total = Zone flow × Simultaneous zones - Design filtration flow:
Design = Total × (1 + Extra%/100) × Safety factor - Micron estimate:
µm ≈ (Minimum passage mm × 1000) ÷ 4 - Element area (screen/disc):
cm² = Design L/min ÷ Loading rate - Loading rate is reduced for moderate or dirty water to reduce clogging.
How to Use This Calculator
- Choose a unit system, then select your emitter type.
- Enter the number of emitters operating in one zone.
- Enter emitter flow, then set simultaneous zones if needed.
- Optionally override with a known peak flow from a meter.
- Pick water source and quality to reflect real conditions.
- Press Calculate and review notes and inlet size.
- Download CSV or PDF for records, quotes, or maintenance plans.
Practical Notes
- Use water testing and field observation to confirm micron targets.
- For surface water, consider staged filtration: media then disc/screen.
- Keep spare elements and plan flushing valves for quick maintenance.
- If pressure loss is high, increase filter size or use parallel units.
A professional overview to support the calculator outputs and field decisions.
Sizing Flow for Drip Zones
Start with the largest irrigation zone that can run together. Zone flow equals emitter flow times emitter count, then divided by sixty. If multiple zones overlap, multiply by the number of simultaneous zones. Add 10 to 20 percent for flushing and small leaks, then apply a 1.10 to 1.35 safety factor for stable sizing. Flow meters give better peak estimates in practice.
Micron Selection and Emitter Protection
Filtration targets should protect the narrowest water passages. A common planning rule is to size the filter opening at one quarter of the minimum passage dimension. For many inline emitters this lands near 120 to 200 microns, while drip tape may need finer ratings. Dirty or surface sources usually justify stepping finer and adding staged filtration. Confirm micron with manufacturer charts and local water tests.
Filter Type Comparison for Gardens
Screen and disc units are compact and easy to service, making them common for wells and municipal supplies. Media filters handle algae and organic debris better, especially for ponds and canals, but need proper backwash flow. When water quality is moderate, disc filters often provide better dirt holding than simple screens at similar micron ratings for gardens.
Pressure Loss and Parallel Units
Every filter adds pressure loss that grows quickly with flow. Keep clean differential pressure modest, often around 0.3 to 0.7 bar depending on pump margin. If estimated loss exceeds your limit, increase filter size or place two units in parallel so each sees half the flow. Parallel sizing reduces loss roughly with the square of flow per unit.
Maintenance Planning and Recordkeeping
Plan cleaning frequency using both water quality and field observation. Install inlet and outlet gauges to track differential pressure and trigger flushing before emitters suffer. For dirty water, schedule inspections weekly at first, then adjust. Keep CSV or PDF exports with dates, micron ratings, and notes to support purchasing quotes and seasonal maintenance routines.
FAQs
1) What micron rating is typical for inline drip emitters?
Most inline emitters perform well around 120–200 µm. Use passage size or the calculator’s recommendation. For dirty or surface water, step finer or add staged filtration to reduce clogging and maintenance.
2) When should I override the flow with a known peak value?
Override when you have a measured peak from a flow meter, pump curve, or mainline test. This is useful when zones overlap, when emitters differ by plant, or when non‑irrigation demands share the same supply.
3) How much extra flow allowance should I add?
Add 10–20% for flushing, minor leaks, and future expansion. If you routinely flush laterals or run fertigation injectors, use the higher end. Keep the safety factor separate so you can audit each margin.
4) Is a media filter necessary for a pond or canal source?
Often yes. Media filtration is strong against algae, organics, and fine suspended solids common in surface water. Many systems use media first, then disc or screen as a polishing stage to protect emitters.
5) What differential pressure indicates cleaning is needed?
Track inlet and outlet gauges. A common trigger is a noticeable rise from clean conditions, or when flow drops at the same valve setting. Many small systems clean at roughly 0.3–0.7 bar (4–10 psi) of differential pressure.
6) Why does the calculator suggest multiple filters in parallel?
Pressure loss increases rapidly with flow. Splitting total flow across parallel units lowers flow per filter, which reduces clean differential pressure and extends run time between cleanings. Parallel layout can also keep irrigation running during servicing.
7) Can I use this calculator to choose a specific brand or model?
Use it to estimate required capacity, micron range, and inlet size. Then compare manufacturer charts for flow versus pressure loss at your micron rating, and confirm compatibility with your water test and maintenance plan.