Daily monitoring is what keeps a fertigation program stable. Because of this, two readings matter more than any single recipe: electrical conductivity and pH. Get them right, and the crop follows.
Why Fertigation EC and pH Matter More Than Any Single Recipe
Electrical conductivity shows how much dissolved salt sits in the water. Therefore it tells you whether the crop is being fed or stressed. pH then decides which nutrients stay available. If pH drifts, iron, manganese and phosphorus can lock up even when the recipe is correct. Meanwhile, the same recipe can behave differently on two farms, because source water differs. For the wider setup, see our fertigation guide.
Start With the Source Water Baseline
Test the raw water before you mix anything. Then record the baseline, so you can compare it later. Hard water carries calcium and bicarbonate, which pushes pH up. As a result, more acid may be needed, and precipitation risk rises. That risk is the subject of our calcium and phosphate mixing note.
The Daily Routine: What to Measure and When
Check the source water once per shift. After that, check the stock solution and the final feed. Because of this order, you can tell where a change started. Record both readings against the crop target, not against last week. Also note temperature, since it shifts conductivity readings. Then flush lines at the end of the day.
What Drift Tells You
A rising EC usually means evaporation or a dosing error. A falling EC often means a clogged injector or low stock concentration. Meanwhile, a sudden pH jump can come from a new water source or a change in acid dosing. Therefore treat every drift as a clue about equipment, not just chemistry.
Common Mistakes in Daily Monitoring
- Measuring only the tank, then assuming the dripper receives the same value.
- Leaving probes uncalibrated for weeks, then trusting the reading.
- Mixing calcium with phosphate or sulfate in one tank, which invites precipitation.
- Ignoring the crop stage, although the target changes with it.
Finally, keep the log simple. A short daily record beats a complex one that nobody fills in. For ratio choices that pair with these readings, see our NPK ratio notes.
Reference: FAO Soils Portal for nutrient management context.
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