"I have a log — I fill it in once a month when I remember." Then a customer complains that a batch of radish is spoiled. When was it sown? Which seeds? What was the temperature that week? "I don't remember exactly." Without a log, answering takes an hour and remains imprecise. With a log — three minutes and an exact answer. But a log only delivers value if it is filled in regularly and in real time — not reconstructed from memory before an inspection.
Quick glossary: Production log — a document where key parameters of the production process are recorded at the moment they occur; the primary tool for operational management and batch traceability. Daily entry — recording parameters that change each day: EC and pH measurements, temperature, irrigation; takes 3–5 minutes when properly organised. Batch — a production unit with a unique identifier from which all input materials and growing conditions can be traced.
Three Levels of Records: Different Frequency, Different Purpose
Not everything needs to be recorded daily — and not everything can wait a month. Proper organisation means each record is made at the right frequency and takes minimum time.
Daily records — parameters that change or need monitoring every day:
- EC and pH of the solution (morning before irrigation and/or after preparing a fresh solution)
- Room or substrate temperature (morning and midday peak)
- Reservoir level or top-up volume
- Any deviations or observations (yellowing leaves, blocked dripper, unusual smell)
- Procedures performed: irrigation, solution preparation, sanitation
Weekly records — parameters and inspections that need regularity but not daily:
- Drain EC and pH (at least once a week)
- Root or plant health inspection by zone
- Fertiliser and water consumption (remaining stock, replenishment)
- Equipment condition: pumps, timers, filters
- Refrigerator temperature and storage conditions
Per-batch records — recorded when opening a new batch or at harvest:
- Batch number, sow date, crop, variety
- Seed source and seed lot
- Substrate: type and supplier
- Harvest date and yield in kg or number of trays
- Where dispatched and with which documents
More on the structure of batch tracking — in the article on production documentation.
Daily Log Format: How to Make It Actually Get Filled In
A log that takes 20 minutes to fill in won't get filled in. A log that takes 3–5 minutes will.
Rules for an effective daily log:
One row — one day. Columns: date, EC, pH, temperature morning/peak, deviations, actions. Everything else only when a deviation occurs.
A log as a weekly or monthly sheet on the wall next to the system is far more effective than a laptop or phone at the other end of the room. Wherever it is convenient to record at the moment of measurement — that is where the log lives.
Numbers in pen, immediately after measuring — not "I'll remember and write it up tonight." Deferred recording means inaccurate data and gaps.
Minimum daily row format:
Date | EC | pH | Temp | Deviation / Action 10.03 | 2.1 | 6.0 | 21/24 | — 11.03 | 1.8 | 6.4 | 20/23 | Topped up 10 L; pH rose after top-off
Where the Log Delivers the Most Practical Value
Detecting trends before a problem appears. pH slowly creeping upward over a week shows in the log before the plant shows symptoms. EC dropping without an obvious cause — a possible signal of a leak or dilution somewhere. On a week's log — the trend is clear. From memory — "seems fine."
Connecting actions to outcomes. "Changed the formula on 3 March — and ten days later yield improved." Without a log, you don't know exactly what you changed or when. With a log — data exists for before-and-after comparison.
Yield reporting and efficiency calculation. Every batch yield is recorded — you can calculate average yield, identify batches that came in below standard, and find what they had in common.
Responding to a complaint. A customer returns a batch citing appearance issues. You look up the batch number, open the record: sow date, seeds, weekly EC, temperature. If there was a deviation — you have an answer. If there wasn't — you have documentary protection.
Connection to HACCP
Production logs are the foundation of HACCP documentation. Critical control points require records that confirm control was exercised. During an inspection — a log that is kept consistently is evidence that the control system is working. A log filled in just before the inspection — looks exactly like that and raises questions.
The minimum HACCP record for food-grade microgreens or leafy greens production includes: finished product storage temperature, sanitation of production surfaces and the growing space, and any process deviations.
Three Mistakes That Cost the Most
Filling the log "later" or reconstructing it from memory. "Later" means evening, which means approximate. "From memory" means inaccurate data. Retrospective entries a week on are invented numbers that look real. Recording at the moment of measurement is the only format that produces accurate data.
Recording only normal values and skipping deviations. "All normal" in every row — either untrue or deviations simply aren't being logged. Deviations and the actions taken are the most valuable part of the log for analysis and for HACCP. If a deviation occurred — record it even if it "has already been corrected."
Keeping the log separate from the measurement location. Log in the office, system in the greenhouse — guaranteed deferred and inaccurate entries. A log on a tablet or paper sheet directly next to the system where measurements are taken — it gets filled in on the spot.
How to Know Logging Is Set Up Correctly
Any question about "what was happening two weeks ago" has an answer within two minutes from the log. EC, pH, and temperature trends are visible over the past month without any mental arithmetic. At every harvest, there is a record that allows full reconstruction of the growing conditions for that batch.
For deeper understanding: Production Documentation: Logs, Batches, Traceability — explains how daily and batch logs combine into a traceability system and how that system protects the producer when complaints arise and during inspections.