Drip Irrigation Filtration

Why the filter is the system's immune system

The emitter's orifice is small — the 2–4 L/h drip emitter's opening is a fraction of a millimetre, and the 10–15cm tape emitter's is smaller still. Anything the water carries that's bigger than that orifice stops at the orifice — and stops it from flowing. The filter is the component that keeps the water's load below the orifice's size, so the evenness the system was designed for holds through the season. A system that's even on install day and uneven by month three is a filtration story, not an emitter story — which is why the filter gets its own guide, and why the common problems guide opens with the clog.

The three filter types

The mesh size (the media filter's) or the groove width (the disc's) is set by the emitter's orifice — the rule of thumb is the filter's rating at or below the emitter's minimum orifice, and the design is where the spec is set from the line's rating. The finer the emitter, the finer the filter — the strawberry's 10–15cm tape wants the tightest spec on the crop list, and the watermelon's 20–30cm emitters the looser one.

Matching the filter to the water — by source

• The borehole. The cleanest common source — the disc filter is the standard, and the watch is the iron: the iron-bearing borehole water clogs the emitters slowly over the months (the "the system is gradually failing" that's the iron's signature). The disc's rinse on the calendar, and the occasional look at what the water does in a jar (the rust colour is the tell), handle most of it. The water quality guide covers the iron's story.
• The dam. The surface water's standard — the sand/media filter first (the seasonal silt and the organic load are what the media bed traps), the disc where the emitter's fine orifice wants it. The intake is the first line of defence — the screen, the protection from the seasonal silt's draw, the position away from the shore's sediment. The water quantity guide covers the intake's engineering.
• The river / the lake intake. The demanding surface water — the two-stage (the media + the disc) is the standard, the intake engineered (the screen, the protection, the position), and the routine tightened in the silt and the algae season. The lake-fed farms (the Naivasha flower operations, the Eldoret lake-water blocks) are the pattern — the algae season is what the routine is sized for, and the maintenance calendar is where the frequency lands.
• The tank (the harvested rain, the stored water). The cleanest source of all — the screen or the small disc at the outlet is the standard, the first-flush on the roof intake the collection's first line. The tank's water is the small plot's and the strawberry bed's standard supply, and the filtration is the lightest of the sources.

The setup — where the filter sits

The filter's position on the line is fixed by the system's logic: after the source's intake (or the pump), before everything else — the valves, the mainline, the regulator, the fertigation injection, all of it downstream of the clean point. The how drip works guide has the head assembly's order; the filter is the head's first component after the delivery. The fittings around the filter (the bypass, the gauges, the backwash valve on the media) are the service access — the filter that's fitted without the service access is the filter that's never serviced, and the install is where the access is built in.

The routine — the calendar that holds the evenness

• The pressure-drop gauge. Across the filter, the gauge reads the clog's tell before the emitters show it: a rising drop is the load building, and the service is the reset. The maintenance guide has the gauge's role; the upgrade adds the gauge where it's missing.
• The disc's rinse. The disassemble-and-rinse — the discs off, the water through, the reassemble. Weekly on the surface water (the filtration guide's setup), monthly on the clean borehole. The ten minutes that hold the evenness.
• The media's backwash. The reverse flow that flushes the media bed — on the calendar, tighter in the silt and the algae season. The backwash valve is the component; the routine is the keeping.
• The seasonal service. The start-up's filter inspection (the media's state, the discs' condition) and the shutdown's clean-and-store — the maintenance guide's two seasonal jobs, the filter's share of both.

The maintenance service runs the routine on the calendar where the operation earns it — the visits on the schedule, the report after each, the small improvements that accumulate. The assessment is where the frequency is set from the source's actual load, not the source's type.

The failure modes — what the skipped routine does

• The slow clog. The season-long emitter blockage that starts as a row and ends as a field — the common problems guide's opening, the filtration story wearing the line's face. The cleaning treatments are the reset; the routine is the prevention.
• The pressure drift. The filter's clog stealing the pressure, the field's far end drying as the season runs — the common problems guide's pressure-loss family, the filter's share of it. The gauge is the tell; the service is the fix.
• The iron's slow work. The borehole's iron building in the emitters over the months — the water quality guide's iron story, the disc's rinse on the calendar is the check. The jar test (the water's colour after the rest) is the farmer's own tell.

The filter that's right for the farm

The spec is set from two numbers: the source's load (what the water carries — the silt, the algae, the iron, the organic) and the emitter's orifice (the size the load has to stay below). The assessment measures the source's actual load — the jar test, the intake's position, the seasonal behaviour — and the design specs the filter from the two numbers. The filter page has the component's range; the cost guide the indicative price of the head's filtration line. The quote is the farm's number, built from the source's actual load.