Calculator Inputs
Example Data Table
| Scenario | Measured EC | Unit | Temp (°C) | Dilution | Corrected EC @ 25°C | Estimated Original EC |
|---|---|---|---|---|---|---|
| Container herb leachate | 1.55 | mS/cm | 23 | DF 1.0 | ~1.61 mS/cm | ~1.61 mS/cm |
| Salty runoff, diluted for meter range | 2.10 | mS/cm | 28 | DF 5.0 | ~1.98 mS/cm | ~9.90 mS/cm |
| Hydro media drainage check | 950 | µS/cm | 25 | DF 1.0 | ~0.95 mS/cm | ~0.95 mS/cm |
Formula Used
Where α = (Temp Coefficient ÷ 100), T is sample temperature, and Tref is reference temperature.
ECoriginal = ECref × DF
Typical factors range from ~500 to ~700 depending on ion mix.
How to Use This Calculator
- Collect leachate consistently (same timing after irrigation, same container or bed zone).
- If EC is above your meter range, dilute with clean water and record the dilution.
- Enter the meter reading, unit, and sample temperature (or leave default 25°C).
- Set dilution factor or volumes, then apply a calibration factor if you know it.
- Click Calculate to see corrected EC, estimated original EC, and approximate TDS.
- Use trends to adjust feeding, flushing, and irrigation scheduling.
Why leachate conductivity matters
Leachate EC is a fast indicator of dissolved salts moving through the root zone. In containers, coco, and raised beds, excessive EC often signals nutrient accumulation, insufficient runoff, or salty source water. Low EC can indicate underfeeding, heavy leaching, or a media with weak nutrient retention. Used routinely, EC helps stabilize crop performance and reduces costly guesswork.
Sampling for repeatable readings
Collect leachate at a consistent irrigation stage, ideally after the media is fully wetted and runoff begins. Avoid the first few drops when dry salts dissolve rapidly. Use clean containers, rinse probes between samples, and record the plant stage, feed strength, and irrigation volume. Consistency improves trend quality more than chasing perfect single values.
Correction improves comparability
Temperature affects conductivity, so correcting to a reference temperature improves comparisons across seasons and locations. If the sample is diluted to fit meter range, the original EC can be back-calculated using a dilution factor. A calibration factor is useful when a meter reads consistently high or low against a known standard solution.
Turning results into actions
Rising leachate EC can be addressed by increasing irrigation frequency, improving runoff percentage, reducing input concentration, or performing a controlled flush. If EC is low and growth is pale, gradually increase feeding and verify pH management. Always consider crop tolerance, climate, and media type, then adjust in small steps.
Example data and logging practice
Example set: Measured 2.10 mS/cm at 28°C, diluted DF 5, coefficient 1.9, calibration 1.00. Corrected EC becomes ~1.98 mS/cm at 25°C, and original leachate EC estimates ~9.90 mS/cm. Record weekly averages and note events like heat waves, fertilizer changes, or heavy rain. A simple log supports early detection and steadier nutrition decisions.
FAQs
It is the electrical conductivity of drainage water leaving the root zone, reflecting dissolved salts from fertilizer, media, and source water.
For intensive crops, measure weekly or after major feeding changes. For slower systems, every two to four weeks is often enough.
Conductivity rises with temperature. Correcting to a reference temperature makes readings comparable across different days, seasons, and growing areas.
Dilute if the meter range is exceeded or the reading is unstable. Record the dilution so the original EC can be estimated accurately.
No. TDS is an approximation based on a factor that depends on ion composition. Use lab testing for precise dissolved solids.
Confirm sampling consistency, check source water EC, then reduce input concentration or increase runoff. Consider a controlled flush if plants show stress.
Yes. The calculations apply to any leachate. The interpretation differs by crop and media, so compare against your own baseline trends.