Troubleshooting

Common Mistakes in Indoor Farming and Agri-Processing, and How to Catch Them

The recurring errors that throw off grow light, nutrient, climate, labor, and packhouse numbers, each with the symptom, the root cause, and a fix tied to a real number.

The most expensive lighting error is sizing fixtures by wattage instead of delivered light. Symptom: leafy greens stretch or pale even though the fixture draws its rated 600 W. Root cause: growers track W/ft2 and never convert photon flux to a daily total. Fix by targeting DLI directly. Lettuce wants 12 to 17 mol/m2/day, fruiting tomatoes 20 to 30. Convert PPFD to DLI by multiplying umol/m2/s by 0.0864 and by photoperiod hours. A 250 umol/m2/s canopy over 16 hours gives 14.4 mol, on target. Run the Grow Light Energy Cost tool on photon output, not just draw.

Nutrient dosing fails most often at the ppm versus EC conversion. Symptom: tip burn on one crop and deficiency on the next from the same recipe. Root cause: mixing the 500 scale and the 640 scale, where EC 1.0 mS/cm reads as 500 ppm on one meter and 640 ppm on another, a 28 percent gap. A second trap is dosing stock concentrate without checking the dilution ratio, so a 1:100 injector fed 150 mL/L stock overshoots target EC by half. Fix: lock one scale, verify injector ratio against a runoff EC reading, and size batches with Nutrient Mix Consumption before you mix.

Climate systems get undersized because planners count sensible heat and forget latent load from transpiration. Symptom: temperature holds at 24 C but humidity climbs, VPD collapses below 0.6 kPa, and botrytis appears. Root cause: a full canopy transpires 0.5 to 1.0 L of water per m2 per day, and each liter removed as vapor carries roughly 2,260 kJ the dehumidifier must handle. Ignore it and you undersize by 20 to 40 percent. Fix: add the latent term explicitly in Climate Control Load, then confirm dehumidification pulls the matching liters per day, not just BTUs of sensible cooling.

Yield per square foot reads artificially low when the denominator is wrong. Symptom: your 4.5 kg/m2 per cycle looks weak against a 6 kg/m2 benchmark. Root cause: dividing harvest by gross building footprint including aisles, headhouse, and cold rooms instead of active canopy. Aisles alone often eat 30 to 40 percent of floor. Fix: measure the lit canopy footprint only, and for multi-tier racks multiply by tier count, so three 40 ft2 tiers count as 120 ft2. Feed canopy area, not gross area, into Yield per Square Foot, and compare like for like across sites.

Harvest labor plans break when built on annual averages. Symptom: a crew sized for the mean runs fine for months, then blows past 20 percent overtime during peak weeks. Root cause: a staggered planting that averages 200 kg/day still spikes to 500 kg/day when several beds mature together. Fix: forecast labor against the peak harvest week from your planting schedule, not the yearly mean. If pickers average 25 kg/hour, that 500 kg day needs 20 labor-hours, not 8. Line up Crop Cycle Planning with Harvest Labor Forecast so staffing tracks the actual maturity curve instead of a flat line.

Cold storage looks half empty on paper yet turns trucks away. Symptom: the system shows 55 percent volume used but receiving cannot place another pallet. Root cause: measuring cubic feet of product instead of usable pallet positions, ignoring aisle, sprinkler, and evaporator clearances plus the ceiling gap. Usable space is typically 60 to 70 percent of gross cube. Fix: count in pallet positions and rate utilization against that, not raw volume. Model it in Cold Storage Utilization, and hold 5 to 10 percent of positions open so putaway and first-in first-out rotation do not stall the dock.

Rejects and water get measured at the wrong place. Symptom: a 3 percent packhouse reject rate that hides an 11 percent true loss. Root cause: counting only culls at the final grader while field trim, wash-line drops, and cooler shrink go untracked, and each stage compounds. Fix: tag rejects by station and total them in Rejection Rate Cost, since removing a cull after grading and packing costs far more than one culled in the field. Water shows the same gap: reporting emitter output while a 0.2 leaching fraction and 85 percent emitter uniformity are ignored understates real draw by about 20 percent in Water Use per Crop.

Packhouse capacity gets quoted from the fastest machine instead of the binding constraint. Symptom: a line rated at 8 tons/hour on the grader actually clears 5 tons/hour. Root cause: sizing throughput on one station while the real bottleneck sits upstream at the wash tank or downstream at manual palletizing, where 4 packers at 1.2 tons/hour each cap the line at 4.8 tons. Fix: rate the line at its slowest station and time each step under load, not by nameplate. Balance stations in Packhouse Throughput so no single point runs above 85 percent while others sit starved and idle.

Published 2026-07-02.