The treatment supplier sees source-water preparation, the grower manages root-zone and nutrient conditions, and purchasing needs operating-cost information. Sharing one EC reading can conceal these different tasks. Start a Southeast Asian project handover by agreeing on sampling locations, units and responsibilities before deciding whether RO is needed.
Identify three different sample types
Source water is measured before treatment or fertiliser preparation. Prepared nutrient solution describes the irrigation input. Drainage or return water represents another location in the operating system. Label every result with point, time, temperature, instrument and unit. Do not treat drainage EC as source-water salinity or use a source-water report in place of nutrient management.
1 dS/m equals 1 mS/cm and 1000 μS/cm. Even with identical units, EC does not identify individual ion concentrations. Two samples with similar EC can have different compositions. Obtain suitable analysis where sodium, chloride or alkalinity matters instead of inferring them from total conductivity.
Respect the limits of general irrigation guidance
FAO's agricultural water-quality guidance addresses irrigation, crops, soils and management conditions. Its classifications are not a universal nutrient recipe or acceptance threshold for every soilless crop. The grower must define crop, substrate, growth stage, recirculation and nutrient objectives. A treatment supplier should not silently take over that agronomic decision.
| Party | Information to provide or confirm |
|---|---|
| Project buyer | Site, source, schedule, budget scope and acceptance coordination |
| Treatment designer | Feed basis, treatment targets, limits and equipment records |
| Grower | Crop, substrate, nutrient plan, targets and abnormal-condition criteria |
| Laboratory | Sample instructions, methods, reports and interpretation limits |
If RO is used, record water before and after treatment separately from the final prepared solution. Reduced source-water salt content does not establish that the resulting nutrient solution suits the crop. Confirm treatment, blending and downstream controls together. Unverified bypass or return-water mixing can change the final input.
Replace verbal handover with a trial record
Agree on representative sample points and operating conditions, collect matching records, and let each party confirm the result within its responsibility. Keep irrigation quantity, source and treated-water indicators, nutrient status and abnormalities. A photograph of a running skid is not enough. State the crop and conditions to which conclusions apply rather than extending them to every crop or season across the region.
For a source-water discussion, send the analysis, grower's objectives and system diagram through the website enquiry page. Supply, agronomy, installation and yield outcomes require separate confirmation. No yield improvement or nutrient formula is promised here.
Source: FAO water quality for agriculture. AI-assisted project handover guidance. Unit conversions are general examples, not results of a Southeast Asian growing trial.