Raw coir carries salts — mainly sodium, potassium and chloride. Washing removes them to deliver a lower, more stable EC, so your fertiliser programme controls the root zone instead of competing with the substrate.
What washing does
Washing flushes soluble salts out of the coir, lowering EC. Extra-washing targets the lowest EC for sensitive and high-value crops.
- Lowers and stabilises EC
- Reduces sodium and chloride
- Cleaner, more predictable nutrition
Washed vs extra-washed
Standard washing suits most crops; extra-washed grades are specified for hydroponic and high-value production where the lowest EC matters most.
Washing is not buffering
Washing lowers salts; buffering pre-loads calcium and magnesium. For most professional crops you want both — washed and buffered.