Hydroponics works in India for a short list of crops (lettuce and other leafy greens, herbs, strawberry, cherry tomato, capsicum, cucumber) grown inside a polyhouse, shade net or building, and it pays only when a buyer for premium produce is already lined up. It needs a reliable power supply, clean water and a trained person who checks the nutrient solution every day, and ICAR-CISH notes that many imported systems were abandoned by owners because of the high system cost, the high cost of nutrient mixes and a lack of know-how.
Hydroponics is a technical enterprise, not a shortcut. The yield gains in Indian trials are real, but they were measured against open-field plots, not against other protected-cultivation systems.
Systems used in India
| System | How it works | Suited crops | Power dependence |
|---|---|---|---|
| NFT (nutrient film technique) | A thin stream of nutrient solution flows past roots in sloping channels and returns to a tank | Leafy vegetables, herbs, strawberry | High: pump on a timer |
| Drip hydroponics (bag or slab in cocopeat) | Nutrient solution dripped on to a solid medium | Indeterminate tomato, cherry tomato, capsicum, parthenocarpic cucumber | Moderate |
| Ebb and flow | Tray is flooded and drained on a cycle | Leafy vegetables, seedlings | Moderate |
| Solid-medium vertical models (CISH pyramid, X-shape) | Short-statured plants in a medium, with timer-based drip | Vegetables, herbs, strawberry | Lower: ICAR-CISH recommends these where power is erratic |
- ICAR-CISH, Lucknow has developed more than ten Indian designs. The vertical double-row NFT model holds 192 plants against 32 in a standard layout, the vertical single-row model holds 160 against 40, and the triangular vertical model holds 80 against 32.
- CISH reports that its NFT designs save 60 to 70% of water and about 40% of nutrients because the solution is recirculated. Pumps can be run on a timer and a solar panel.
Crops that make sense
- CISH lists tomato, capsicum, cucumber, lettuce, broccoli, red cabbage, Swiss chard, kale, coriander, methi, mint, basil, strawberry, blueberry and some cut flowers (marigold, carnation, chrysanthemum, rose) as suitable.
- Choose crops that are high in value, high yielding and harvested many times. Staple field crops and cheap vegetables do not recover the cost of the system.
- Indian trial result: in a published comparison, lettuce gave 169% more yield and spinach 190% more in a circulating NFT system than in an open field, and 107% and 124% more in a non-circulating hydroponic system (Acharya et al., 2022, Journal of Soil and Water Conservation). Hydroponic leaves also had higher soluble sugar and higher nitrate, phosphorus and sulphur content.
Nutrient solution, pH and EC
- Nutrients are mixed as two stock solutions, A and B, so that calcium nitrate does not precipitate with phosphates and sulphates. Stock strength should stay below 3x. ICAR-CISH has developed a low-cost 3x A and B mix (one litre in 300 litres of water) for leafy vegetables, solanaceous vegetables, strawberry and cucumber; ask CISH, Lucknow how to obtain it.
- Most nutrients are available between pH 5.5 and 6.5. Check and correct pH twice a day, especially after topping up the tank; acids (phosphoric, nitric, citric) lower it and potassium hydroxide or sodium bicarbonate raise it.
- EC measures only total strength, not the balance of individual nutrients. In a manual system check it daily. CISH's ranges for subtropical conditions (20 to 25 degrees C) are in the table below.
| Crop | pH | EC (mS/cm) | TDS (ppm) |
|---|---|---|---|
| Lettuce | 5.5 to 6.5 | 0.8 to 1.2 | 400 to 850 |
| Pak choi | 6.5 to 7.0 | 1.5 to 2.0 | 1,050 to 1,400 |
| Capsicum | 6.0 to 6.5 | 1.8 to 2.2 | 1,250 to 1,540 |
| Cucumber | 6.0 to 6.5 | 1.7 to 2.4 | 1,150 to 1,750 |
| Tomato | 5.5 to 6.5 | 2 to 5 | 1,000 to 2,500 |
Water, temperature and oxygen
- Use neutral, low-salt water. Test your water for EC and pH before buying a system; hard or saline borewell water pushes EC up before any nutrient is added.
- Leafy and exotic vegetables grow best with a solution temperature of 15 to 18 degrees C and tolerate down to 7 degrees C. Tomato and capsicum prefer 18 to 27 degrees C and cucumber 15 to 32 degrees C. Growth is limited below 10 or above 35 degrees C, so a chiller or a shaded, insulated tank may be needed in a hot summer.
- Roots need oxygen. Dissolved oxygen falls as the solution warms, so aerate or circulate it. A pump or power failure of a few hours in a hot polyhouse can wilt an NFT crop, which is why a generator or battery back-up and a spare pump belong in the budget.
Pests and diseases
- Soil-borne problems fall, but root rot (Pythium) can spread through a shared solution within days. Keep tanks covered, clean channels between crops and keep the solution cool.
- Whitefly, aphids, thrips and mites still reach the crop inside polyhouses. Use insect-proof net on all openings, yellow sticky traps and a double-door entry. For any spray on a crop eaten fresh, use only products labelled for it and follow the label; ask your KVK or the state horticulture department.
💡 Tip: Start with a small NFT or solid-medium unit of a single crop such as lettuce or basil, and sell to a hotel, restaurant, salad packer or supermarket before building anything larger. Most failures reported in India come from high setup cost and lack of technical skill, not from the plants.
Cost and returns
- No audited Indian cost or profit data for commercial hydroponic units was found in primary sources, and published business-plan figures vary widely and are mostly brochure estimates. Treat any "per sq ft profit" claim as unverified.
- To check a proposal, write down: system cost per plant site (channels, pumps, tanks, sensors, polyhouse), electricity and back-up cost, nutrient cost per crop cycle, labour, packing, and the price a named buyer will pay per kg. Then divide yearly cost (including depreciation and interest) by the kg you can sell in a year.
- Ask for written quotes from at least three suppliers and visit working farms that have operated for more than two years, not new demonstration units.
Market and risks
- Buyers are hotels, restaurants, cafes, salad and pizza chains, modern retail and online grocers. They need steady weekly supply, clean packing and a cold chain, and a small farm cannot easily meet this alone. A group sale through an FPO may help.
- Lettuce, herbs and strawberries spoil fast. Plan packing and cold storage before the first harvest; see cold storage subsidy.
- Be careful with suppliers who sell turnkey kits with promised buy-back or "assured income". Check what the contract says about price, quality grade and who pays for rejected produce.
- Hydroponics, aquaponics and vertical farming have been proposed as components under the Mission for Integrated Development of Horticulture (MIDH), but a confirmed per-unit subsidy rate was not found. Ask the district horticulture officer and see the subsidy finder and polyhouse subsidy pages for the structure itself.
- Related guides: strawberry, solar pump for power back-up.
Sources
- Singh and Rajan, Vertical hydroponics: A future technology for urban horticulture, Indian Horticulture, March-April 2022 (ICAR-CISH)
- Acharya et al. 2022, Yield and quality attributes of lettuce and spinach grown in different hydroponic systems, Journal of Soil and Water Conservation
- Vertical Farm Daily, Indian government aims to boost farming through hydroponics and aquaponics (secondary source)