About this module
Level 1 fed a household. Level 2 feeds customers: restaurants, shops, schools and offices that want fresh greens grown close by.
Who it is for. People who have finished Hanging Garden Technology (Level 1), or who can show the same skills. National Proficiency II covers varied work done under limited supervision.
CTVET status. No CTVET programme for vertical gardening or hydroponics was found. This module is not a CTVET curriculum.
Bridge from Level 1: what you already know
- Safe containers, the wet-soil weight rule and emptying standing water weekly
- Measuring sun hours and planning a space
- Sack, bottle, bucket, tyre and keyhole builds; drainage holes; bottle drip
- Soil mixes, carbonised rice husk and container sizes
- Crops, days to harvest and thinning
- Watering, safe feeding, neem and soap sprays, reading the plant
- Harvest records and the savings sum
Level 1 did not cover hydroponics, large rooftop installations or wall-fixing engineering. This manual covers hydroponics and teaches you when to call an engineer.
How the module works
Each unit has learning outcomes, performance criteria, the range and the evidence your assessor needs. You are judged Competent or Not Yet Competent. About 70% of the time is practical, following CTVET's Oil Palm programme split of about 30% school and 70% workplace.
Unit 1 · Survey a site and plan safely
Before you build for a client, check the sun, the water, the weight and the safety.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 1.1 Survey the site | records sun hours, water source, drainage and access |
| 1.2 Check the weight | works out wet weight and knows when to call an engineer |
| 1.3 Judge water safety | refuses drain water and applies the safety barriers |
Range. Two client sites. Evidence. Survey forms; weight sums.
Weight
Wet garden soil weighs about 1,600–2,000 kg per cubic metre; a light mix weighs about 640 kg per cubic metre and can cut planter weight by over 60%. Water weighs 1 kg per litre, so a full 200-litre tank weighs about 200 kg.
Roofs and walls. For any rooftop or large wall installation, get a structural engineer to check the load. Use fall protection and never work alone at height.
Water safety
- In Takoradi, some farmers have watered crops from highly polluted drains; in Accra, vegetables from city farms often carried germs and worm eggs.
- WHO guidelines use several "barriers" between dirty water and the person eating the food.
- In Ghana, letting water settle for two days removed almost all worm eggs; sand filters and a cloth over the watering can also helped.
- Drip watering gave far cleaner lettuce than watering cans.
Your rule: use tap, borehole or rain water only. Never drain or gutter water.
Weight sum
A wall rack holds 20 pots of 10 litres each, filled with wet soil at 1.8 kg per litre. What does it weigh? What if you use a light mix at 0.64 kg per litre?
Two surveys
- Survey two sites: sun hours, water, drainage, access, wall or roof.
- Work out the wet weight of your planned system.
- Say whether an engineer is needed.
Water source
Where does water come from at your home? Is it safe for a garden?
Unit 2 · Build vertical systems at scale
Going up, not out, lets you grow a lot in a small space.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 2.1 Build a rack | builds an A-frame or wall rack of gutters, pipes or bottles |
| 2.2 Fit irrigation | fits a gravity or pumped drip line with tank, filter and return |
| 2.3 Fix safely | fixes and levels structures and keeps them mosquito-free |
Range. One vertical system. Evidence. Built system; water flow test.
Systems
- Pipe (NFT) system: plants sit in holes in pipes, with a thin film of solution flowing through on a slight slope and returning to a tank.
- Bottle rack: recycled bottles on a wood or bamboo frame on a slope, fed by gravity drippers from a tank.
- Site needs at least 6 hours of sun, nearby water and protection from birds and animals; in the tropics, 30–50% shade helps.
Ghana examples
- Farm Estate near Accra runs a vertical hydroponic farm and sells to more than 10 retail chains, at markets and online. Power cuts disrupt its lighting.
- Africa House runs a vertical system in Keta and has trained over 2,000 people.
- Jasey Farms in Sunyani grew hydroponic lettuce, starting from a backyard.
Build a rack
- Build an A-frame of pipe or gutters, or a bottle rack.
- Fit a tank, filter and return line.
- Test the flow and fix leaks.
- Fit lids so no water stands open.
Material costs
Price PVC pipe, gutters, a 200 L tank and a small pump in Takoradi.
Unit 3 · Prepare soil-free growing media
The growing medium holds the plant up. It must be clean, airy, and hold water without staying soggy.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 3.1 Prepare media | carbonises or ferments rice husk; washes cocopeat |
| 3.2 Clean equipment | sterilises trays and pots between crops |
| 3.3 Choose media | chooses a medium for each system |
Range. Three media. Evidence. Prepared media; cleaning record.
Good media
Suitable media include small stones, sand, carbonised or fermented rice husk and coconut fibre. A good medium is clean, dark, light, cheap, and holds water but drains.
- Rice husk: carbonise it in small, watched fires, or ferment it by soaking for 15–20 days, washing, soaking in 1% bleach and sun-drying.
- Cocopeat from coastal palms can be salty; soaking for 2–3 days greatly reduced the salt. This matters near Takoradi's coast.
- Cleaning: wash trays in 1% bleach, rinse and dry in the sun.
Burning husk. Work outdoors, away from buildings, never leave the fire, and keep water ready.
Three media
- Carbonise one bag of rice husk.
- Wash a block of cocopeat and test the run-off with an EC meter.
- Clean a set of trays.
Local media
List three free or cheap materials near you that could be a growing medium.
Unit 4 · Grow without soil: simple hydroponics
Hydroponics feeds plants through water. The simplest kind needs no pump and no electricity.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 4.1 Run Kratky | sets up and runs a no-pump system in bottles, buckets and tanks |
| 4.2 Run floating rafts | runs a floating-raft system with and without air |
| 4.3 Run NFT | runs a pipe system and fixes clogging |
Range. Three systems, one lettuce crop each. Evidence. Working systems; crop records.
The Kratky method (no pump)
- Fill the container once. Only the bottom of the net pot touches the solution. As the level drops, roots grow into the moist air gap. Never top up after the roots grow out, or they drown.
- A 4-litre bottle with hydroponic fertiliser grows a lettuce in about 6 weeks from seed. A 20-litre bucket holds 3–4 lettuce.
- A lidded tank lined with black polythene, with a polystyrene lid, grows lettuce about 5 weeks after transplanting. Plant one tank each week for a steady weekly harvest. It suits schools because it needs no weekend watering.
- Keep containers dark so algae do not grow.
- Kratky works best for leafy crops and herbs; its inventor calls Kratky tomatoes impractical.
Floating rafts
Polystyrene sheets float on the solution. With no air pump, stir by hand several times a day, more in the heat.
Ghana cost
In 2021, simple homemade systems cost from about GH¢100 and standard ones GH¢220–500, and a Cape Coast company had trained over 500 farmers. Check current prices.
Mosquitoes. Every tank needs a tight lid. Use Bti or small fish if needed.
Three systems
- Set up a Kratky bottle, a Kratky tank and a floating raft.
- Plant lettuce in each and record growth weekly.
- Compare: cost, work, yield.
School idea
Plan a Kratky tank for a school: size, cost, crop calendar.
Unit 5 · Mix and check nutrient solutions
In soil-free growing, the solution is the soil. Check it like a doctor checks a pulse.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 5.1 Mix to a target | mixes solution to a target EC and checks the water first |
| 5.2 Control pH | measures and adjusts pH; calibrates meters |
| 5.3 Read the plants | reads symptoms and adjusts or replaces the solution |
Range. All Unit 4 systems. Evidence. EC and pH log; calibration record.
EC and pH
- EC (electrical conductivity) shows how strong the solution is. 1 dS/m = 1 mS/cm = 1,000 µS/cm. Water up to about 1,000 µS/cm can be used.
- pH: most crops do best at 5.5–6.5. Outside that, iron, calcium and magnesium get locked out. Find the acid dose on 1 litre first, then multiply for the tank.
- If EC rises in hot weather, plants are drinking more water than nutrients: add water. Best solution temperature is 18–28 °C. Raise EC slowly, by no more than 0.5 at a time.
- Kratky lettuce did well at about EC 1.5; one guide uses about 1.25.
- Free calculators can work out recipes from the fertilisers you can buy.
Heat and lettuce. Lettuce solution warmer than about 26 °C can make lettuce bolt and taste bitter. Takoradi is often hotter. Shade tanks, use heat-tolerant varieties, and try other leafy crops.
Acids and bleach. Wear gloves and goggles. Always add acid to water, never water to acid. Store chemicals locked and labelled.
Solution log
- Calibrate the EC and pH meters.
- Mix a solution to EC 1.5 and pH 6.0.
- Record EC, pH and temperature twice a week in every system.
Your water
Measure the EC of your tap or borehole water.
Unit 6 · Water, protect and harvest for market
Steady, clean, well-packed produce every week is what buyers pay for.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 6.1 Manage water | sizes rainwater storage and uses drip |
| 6.2 Control pests | applies IPM in vertical systems |
| 6.3 Harvest for market | harvests, washes, packs and records; plans weekly supply |
Range. One crop cycle. Evidence. Water plan; IPM log; harvest records.
Water
A 20 m² roof collects about 2,000 litres from 100 mm of rain, enough for two 1 m² micro-gardens for a year. Drip and rainwater harvesting reduce demand on city water.
Pests
Some city growers in Kumasi used banned pesticides and sprayed during harvest; FAO recommends IPM, and an Accra group that adopted IPM sold lettuce through branded kiosks.
Yields
| Crop | Per m² | Harvest |
|---|---|---|
| Lettuce | 20–25 heads | 24–32 days |
| Basil | 8–40 plants | from 35–42 days |
| Tomato | 3–5 plants | first fruit at 50–70 days |
FAO micro-gardens can yield up to 10 kg per m² a year of leafy crops.
Market harvest
- Plan a weekly planting calendar for steady supply.
- Harvest, wash in clean water, pack and label one batch.
- Record weight and any pests found.
Rain tank
Measure a roof and work out how much rain it collects from 100 mm.
Unit 7 · Run a garden installation and supply business
You can earn twice: once for building the garden, and again for keeping it growing.
Competency standard
| Learning outcome | Performance criteria — the trainee… |
|---|---|
| 7.1 Price installations | costs and prices an installation and a maintenance contract |
| 7.2 Sell produce | sells microgreens, herbs and lettuce; plans subscription boxes |
| 7.3 Serve clients | markets the business and serves clients with disabilities |
Range. Two clients. Evidence. Quotes; marketing plan.
Demand
- In Accra, young skilled people living in flats were most interested in vertical gardens, driven by high vegetable prices; researchers recommended a subscription model.
- City market gardeners in Kumasi earned up to US$800 a year, but growers were poorly organised and paid for production from their own savings.
- Farm Estate uses QR codes to show buyers each crop's journey from seed to harvest.
Microgreens
Microgreens are harvested 7–21 days from seed, about 4–8 cm tall. They keep 10–14 days cold at about 5 °C but only 2–4 days at room temperature, so a cool chain matters. Buyers include restaurants, grocers and subscribers.
Pricing an installation
Price = materials + labour (hours × rate) + transport + profit Maintenance contract = visits per month × (time + travel + nutrients)
Quote
Materials GH¢1,200, 12 hours of labour at GH¢20, transport GH¢100. Add 30% profit. What is the price? A monthly maintenance visit takes 2 hours plus GH¢30 travel and GH¢40 nutrients. What is the monthly fee at GH¢20 an hour plus 30%?
Location settings that give good returns
- Hotels, restaurants and guest houses in Takoradi and on the coast
- Schools (Kratky tanks need no weekend watering)
- Offices and banks wanting green walls
- Flats and estates with little ground space
- Near your customers, so produce arrives fresh
Business ideas and ingenuity
- Install and maintain gardens for homes, schools and hotels
- Weekly microgreen and herb deliveries to restaurants
- Subscription vegetable boxes
- Kratky starter kits for households
- Training workshops for schools and churches
Market yourself
- Before-and-after photos of every installation.
- WhatsApp Business catalogue with prices for kits and installations.
- A demonstration garden at your home or the Hub.
- A QR code or label showing where your produce was grown.
Accessibility
Soil-free and micro-garden systems need less physical effort. Build tables and A-frames at a height wheelchair users can reach, keep paths wide and clear, lock tank lids and keep chemicals out of reach.
Quote and plan
- Write a quote for each Unit 1 client.
- Write a maintenance contract.
- Make a one-page marketing plan.
Restaurant visit
Ask a restaurant which greens and herbs they buy, how often and at what price.
Glossary
| Term | Meaning |
|---|---|
| EC | Electrical conductivity: how strong a nutrient solution is |
| Hydroponics | Growing plants without soil, in water with nutrients |
| Kratky | A no-pump hydroponic method |
| Microgreens | Seedlings harvested when very young |
| NFT | Nutrient film technique: a thin film of solution in pipes |
| pH | How acid or alkaline a solution is |
Logbook
- Unit 1: survey forms; weight sums
- Unit 2: built system; flow test
- Unit 3: media preparation; cleaning record
- Unit 4: crop records for three systems
- Unit 5: EC and pH log; calibration record
- Unit 6: weekly calendar; harvest records
- Unit 7: quotes; maintenance contract; marketing plan
- Every homework, dated
Self-check quiz
- What does a full 200-litre tank weigh?
- When must you call a structural engineer?
- Which water may you use?
- Why must you never top up a Kratky container after roots grow out?
- Why must tanks have lids?
- What pH range suits most crops?
- What does rising EC in hot weather mean?
- Why is warm solution a problem for lettuce?
- How long do microgreens keep at room temperature?
- Write the installation price formula.
Further reading and sources
Best next reads: your Level 1 manual; the University of Bologna simplified hydroponics booklet; Kratky's no-pump method; the Hub's Money Skills manual.
What this module does not cover: greenhouses, large commercial hydroponic farms, aquaponics (see Fish Farming Level 2) and greywater systems.
Every source used in this manual is listed, with links, in the Teacher Copy.