ข้อเท็จจริงสำคัญ

• Drain-to-waste systems use runoff to flush salt build-up — typically 10–20% runoff per irrigation
• Runoff EC higher than input EC indicates salt accumulation in the medium
• Runoff EC lower than input EC indicates the plant is consuming more nutrients than it receives
• Runoff pH outside 5.5–6.5 signals a root zone chemistry problem requiring correction
• Recirculating systems capture and reuse runoff — less waste but requires regular solution changes
• Coco coir growers typically target 20–30% runoff per feeding to maintain a clean root zone