Hydroponics Resource Center: NFT, Dutch Bucket & Vertical Farms

NFT (Nutrient Film Technique) uses PVC channels with a continuous 1–2mm film of nutrient solution. Best for lettuce, basil, pak choy and other short-cycle leafy crops. Lowest capex among hydroponic systems — around ₹1,800–2,400 per sqft of growing area inside a polyhouse.

Dutch-bucket (Bato bucket) systems use individual 10-litre buckets filled with cocopeat or perlite, fed by drip irrigation with recirculating drainage. Required for tomato, capsicum, cucumber and other long-cycle vining crops. Capex lands around ₹2,500–3,200 per sqft including the polyhouse.

Vertical / indoor farms stack NFT or aeroponic layers under LED lighting in insulated containers or buildings. Capex is the highest at ₹3,500–4,500 per sqft of footprint (delivering 4–6× the growing area through stacking). Justified by zero pesticide residue, year-round consistency and proximity to premium retail.

For leafy greens: EC 1.2–1.8 mS/cm, pH 5.8–6.2. For fruiting tomato/capsicum: EC 2.4–3.2 mS/cm rising through the crop cycle, pH 5.8–6.2. For strawberry: EC 1.4–1.8 mS/cm, pH 5.5–6.0.

Use a two-tank A+B nutrient system. Tank A holds calcium nitrate; Tank B holds the phosphate and sulphate salts. Mixing them undiluted causes calcium phosphate precipitation that clogs drippers.

Measure EC and pH at least twice daily during early operations. A handheld Hanna or Bluelab meter is sufficient. Calibrate weekly with buffer solutions. Replace nutrient solution in recirculating systems every 7–14 days depending on plant uptake.

Lettuce NFT (4,000 sqft, ~12,000 plant sites): 8–10 harvests/year × 8–10 tonnes per harvest at ₹150–250/kg wholesale to HORECA. Payback in 2–3 years.

Cherry tomato Dutch-bucket (4,000 sqft): 18–25 tonnes/year. Selling B2B to premium retail or direct-to-consumer subscription boxes lifts realised pricing 40–60% over mandi.

Indoor vertical basil (1,000 sqft footprint, 4 layers): 6–8 tonnes/year of cut basil at ₹300–500/kg for premium retail and cloud-kitchen supply. Highest margin per sqft but requires consistent quality control.