- Use the spatial and time pattern of a symptom.
- Verify a correction with measurements.
- Clean and document a complete service cycle.
01 / Establish the pattern
Decide whether the problem affects one plant, one branch, a crop batch or the whole system. Check what changed before the symptom: solution, source water, weather, power, lighting, transplant batch or maintenance.
Stabilize basic delivery first. A pump fault, dry plug or saturated root zone should be addressed before interpreting leaf color as a fertilizer deficiency. Preserve a representative sample and the records when specialist diagnosis may be needed.
| Pattern | First measurements | Useful distinction |
|---|---|---|
| One wilted plant | Local delivery and root/plug contact | Plant-position problem versus shared reservoir. |
| One failing branch | Installed flow, obstruction and level | Distribution problem versus nutrient recipe. |
| Whole crop after mixing | Batch grams, volume, EC/pH, source water | Dosing or water change versus gradual deficiency. |
| Gradual root decline | Temperature, oxygen, drainage and sanitation history | Root environment and possible disease. |
| Uneven leaves at bed edges | Light, airflow and moisture profile | Environment versus a uniform feed concentration. |
Reading: Small-scale hydroponics ↗
02 / Change one thing and verify
Write the working hypothesis and the observation that would support it. If an emitter is blocked, measure its output before and after service. If concentration is wrong, reconstruct the batch mass and final volume.
Avoid adding several nutrient products at once. You can create antagonisms, increase salinity and erase evidence of the original fault. If the diagnosis remains unclear or disease spreads, use an extension diagnostic service rather than escalating guesses.
Reading: Electrical Conductivity and pH Guide for Hydroponics ↗
03 / Clean first, disinfect second
Disconnect equipment as its instructions require. Remove plant material and deposits mechanically, then wash accessible surfaces. Organic debris can reduce the effectiveness of a disinfectant. Apply a product appropriate to the surface and intended use, respecting its labelled concentration, contact time and rinse requirements.
Do not mix cleaners, especially chlorine products with acids or ammonia. Keep cleaning solutions out of occupied fish or plant systems. Disassemble screens, emitters and corners that a quick rinse misses; preserve established aquaponic biofilters through their separate maintenance protocol.
- Isolate the empty component and collect remaining solution.
- Remove roots, sediment and biofilm with suitable dedicated tools.
- Wash and rinse as the material instructions require.
- Disinfect only with an appropriate labelled procedure; record product, dilution and contact time.
- Rinse when directed, reassemble, and test clean-water flow and leakage before returning to service.
Reading: Clean and disinfect the greenhouse ↗
04 / Close the incident
Record cause, evidence, action and successful retest. Add an inspection or design change that would have detected the fault earlier. Replace a hidden connection with a serviceable one when access caused the delay.
Keep healthy propagation material separate from dirty production tools. Review recurring failures by frequency and crop impact; the most useful upgrade may be better access or a simple level marker.
FIELD QUESTIONWhy should you record an intervention that did not work?
It prevents repeated guesses, preserves the timing of the problem and helps the next diagnosis distinguish cause from coincidental change.
Parts & buying criteria
Showing nutrient film technique. Quantities describe the teaching model. Specify real working volume, support, fittings and instruments for your installation.
01Reservoir1 · illustrated quantity+
Holds the recirculating nutrient solution. This is the common sampling and refill point for both channels.
Inspect: In cutaway view, compare the water surface with the pump intake. The drawing leaves room above the water; it does not specify a working volume.
Maintain: Record the level before adding water. Inspect the cover, clean accessible deposits and keep the intake submerged during use.
Opaque, cleanable container rated by its manufacturer for the intended use; accessible lid and drain.
Supplier links can be added by the publisher. The criteria stand independently.02Pump & supply1 · illustrated quantity+
Lifts solution from the reservoir to the channel inlets. Cyan packets indicate the direction of delivery.
Inspect: Follow the rising supply pipe and its branch to each channel. Both inlets need an observable supply.
Maintain: Disconnect power before opening the pump. Inspect its inlet screen and confirm both branches flow after reassembly.
Compare the pump curve at the installed lift and pipe resistance; include service access and replacement availability.
Supplier links can be added by the publisher. The criteria stand independently.03Growing channels1 · illustrated quantity+
Contain the shallow stream beneath the plants and guide it toward the return.
Inspect: Open the cutaway to find the channel floor beneath the roots. The slope is exaggerated for reading.
Maintain: Look along each channel for ponding, debris or an obstructing root mat; inspect the outlet before changing the pump.
Removable covers, supported slope, smooth cleanable surfaces and outlets accessible with plants in place.
Supplier links can be added by the publisher. The criteria stand independently.04Plant baskets6 illustrated · illustrated quantity+
Bridge the opening in the channel cover while allowing roots to pass through.
Inspect: In exploded view, the baskets lift above the channels. The open slats reveal the relationship between support and roots.
Maintain: Check that each rim sits securely and that roots are not pinched at transplanting or inspection.
Match the basket rim and hole diameter; allow removal without damaging adjacent plants.
Supplier links can be added by the publisher. The criteria stand independently.05Support mediumFor 6 baskets · illustrated quantity+
The illustrated expanded clay supports the seedling in its basket. The channels are not filled with aggregate.
Inspect: Select the brown pebbles and separate the basket in exploded view. Media texture is simplified.
Maintain: Remove loose particles before installation. Inspect whether the starter plug stays appropriately moist.
Select a stable grade that stays in the basket; compare water retention, dust and cleaning requirements.
Supplier links can be added by the publisher. The criteria stand independently.06Gravity return1 · illustrated quantity+
Collects channel outflow and brings it back to the reservoir without a second pump.
Inspect: Trace the low ends of both channels into the common return. Inspect the full path before assuming the circuit is clear.
Maintain: Remove obstructions and check for leaks. Test drainage with the pump off during commissioning.
Removable unions, supported pipe and sufficient drain capacity under the actual installation conditions.
Supplier links can be added by the publisher. The criteria stand independently.Evidence beside the lesson.
Source checks: September 2026. The geometry, inspection exercises and worksheets are original teaching material. The named organizations have not endorsed or reviewed this site.
Published recipe rates and planning ranges retain their source context. Calculator equations are accounting tools; they do not predict uptake, yield, toxicity or safe stocking. Model dimensions, water speeds, roots and fish counts are illustrative. Verify species, crop, source water and product labels for a real system.
- University of Minnesota ExtensionSmall-scale hydroponics ↗
Root support, transplanting, light, aeration and cleaning.
- Oklahoma State University ExtensionElectrical Conductivity and pH Guide for Hydroponics ↗
Water analysis, salinity, pH and monitoring.
- NSW Department of Primary IndustriesClean and disinfect the greenhouse ↗
Physical cleaning followed by appropriate disinfection.
The next useful connections.
Choose media by water, air and service
Compare coir, mineral wool, expanded clay, perlite and propagation plugs in the system that will irrigate them.
6 min + guided practice →Build, operate & troubleshootCommissioning and daily care
Turn assembled equipment into a repeatable operating system, with a first-crop checklist and a useful log.
6 min + guided practice →