Hydroponics for Beginners in Ghana

The bucket is the easy part

Can you grow lettuce in a bucket on a veranda in Kasoa? Yes. People do it every month, and the first crop often looks better than the one in the soil next door. The trouble starts in week three, when the water turns green, the roots brown and the plants stop putting on leaves. The bucket was never the problem. The water, the heat and the feed were.

Hydroponics means the roots sit in a water solution that carries everything the plant would normally take from soil. You control the nutrients exactly, you save the space that soil would use, and you avoid many of the soil diseases that wreck a field of vegetables. In return you take on a daily job. The plant depends on you for water, oxygen, feed and temperature in a way a field crop does not.

Treat the first few months as a learning season. Grow one crop in one system, keep a notebook, and change one thing at a time. Farmers who try three systems and four crops at once usually end up with nothing they can explain.

What to grow first in Ghana's heat

Lettuce is the usual first crop because it is quick and forgiving, but it is also sensitive to heat. In the dry months of the north and the hottest weeks in the south it bolts, sending up a flower stalk and turning bitter. Pick the crop for the season you are in, not for the magazine picture.

Those times are typical for a well-run system and vary with the variety and the weather, so keep your own harvest dates from the first cycle. Herbs such as basil and mint are a good first project in Ghana because they tolerate warmth and sell by the bunch, which lets a small grower sell in quantities that suit a home kitchen.

Avoid fruiting crops such as tomato and cucumber for your first system. They need far more light, a stronger support structure and a more complex feed programme, and they belong in the next stage once the basics run smoothly.

Four systems you will hear about

Hydroponic systems are named for the way the water reaches the roots. Each has its own pump needs, skill level and failure points. The table below sets them out in the order most beginners should try them.

For a first project in Ghana, many growers choose DWC with a small air pump. It works without a flow pump, the roots stay wet all the time, and the bucket is easy to move into the shade. NFT gives more plants per square metre, but a failed pump on a hot afternoon can kill a whole channel before anyone notices. Only move to NFT after you have a power backup that you trust.

Buy the simplest version that does the job. A clear container with a lid, a net pot, an air pump and a stone is enough to learn on. Ask the supplier which parts are standard and easy to replace in your town, because a broken fitting in a week without a spare can cost the crop.

Where to set it up in Ghana's heat

Light and heat decide where a hydroponic bench works. Most leafy crops want good light for many hours, but the full midday sun in Accra, Kumasi or Tamale can heat a reservoir far beyond the range that roots tolerate. A tank that sits in direct sun on a black plastic stand can reach temperatures that cook the roots within a single afternoon.

Site the system where it gets strong light in the morning and shade in the hottest part of the day. A shade cloth, a north-facing veranda, the side of a building or a corner under a tree all work. Paint or wrap the reservoir in a light colour, or put it in a shaded box, and cover the top so light cannot reach the water. Light on the water grows algae, which uses up oxygen and nutrients and blocks the drip lines.

Keep the bench off the ground and out of the path of dust and animals. In the harmattan months, fine dust settles on the leaves and in the water, so cover the tanks at night and rinse the plants gently every week. Poultry and dogs should be kept well away from any system that holds the water your food crop drinks, because droppings in a reservoir carry bacteria straight into the roots.

Water: source, filter and pH

The water you start with matters more than most beginners expect. Tap water, borehole water, rainwater and well water all carry different minerals, salts and microbes. Borehole water in some parts of the country is hard, which means it carries a lot of calcium and magnesium, and that changes how the nutrient mix behaves. Rainwater is usually soft and clean, but only if the roof and the tank are clean too.

Test the water before you build the system. The water utility serving your town, the district environmental health office and private laboratories can all run basic tests. Ask for the electrical conductivity and the pH, plus any note about the hardness. Write the results down and check them again every season, because a borehole can change with the seasons.

The pH of the solution controls how well the plant can take up nutrients. Most leafy crops do well when the reservoir sits between about 5.5 and 6.5, and the pH drifts over time as the plants take up nutrients. Measure it every few days with a meter or a reliable test kit. Use the pH up and pH down products recommended for your nutrient brand, add small amounts, stir and measure again before adding more.

1. Fill the reservoir with the water you plan to use.
2. Measure the starting pH and write it down.
3. Add the nutrient stock, then measure again once the solution is mixed.
4. Adjust the pH in small steps, stirring and waiting between each dose.
5. Record the final pH and the feed strength reading.

A simple particle filter on the water line keeps sand and rust out of the drippers and the air stone. It costs little and saves hours of cleaning later.

Nutrients: buy the right stock and mix it in order

A hydroponic nutrient is not the same as garden fertiliser. Most commercial hydroponic feeds come as two or three concentrated stock solutions, labelled A, B and sometimes C, plus separate micronutrients. The plant needs calcium, nitrogen, potassium, magnesium and the trace elements, and the stocks are balanced so that they dissolve without dropping out of solution.

Buy from an agro-input dealer or a supplier who can show you the label and a crop guide. Check that the product is still in date and stored away from heat. Ask whether the supplier has stock in your region, because a delayed order leaves a crop hungry in the middle of a cycle. Some growers in Ghana source a basic kit from abroad through online suppliers, and that route is worth comparing with local stock once you have the freight and customs figures for your country, so check current rates before you order.

Mix the stocks one at a time. Add the A stock to a measured volume of water, stir until it dissolves, then add the B stock and stir again. Never pour the concentrates into each other before water is present, because calcium and sulphate or phosphate can form a solid that blocks the system. Follow the label for the dose per litre and for the order of the stocks. Once the solution is mixed, check the meter reading against the guide for your crop.

Keep a written feed schedule. Seedlings need a weaker solution than mature plants, and the strength should drop as the plants approach harvest in many systems. Top up with plain water when the level falls, and make up a fresh full batch of solution when the reservoir is due for a change, which is usually every one to two weeks depending on the size of the tank and the number of plants.

Power cuts and the pump: a worked sum

Power is where many hydroponic systems in Ghana fail. A pump that stops for three hours on a hot afternoon can leave the roots short of oxygen, and a long outage can kill a crop. Ghanaians have a name for it, dumsor, and a good system plans around it.

Work out the energy first. Suppose you run a DWC tank of 100 litres with a 30-watt air pump for 12 hours a day. That is 0.36 kilowatt-hours a day, or roughly 11 kilowatt-hours over a 30-day month. Multiply that by the tariff your distribution company charges, ECG in the south or NEDCo in parts of the north and east, and check the current rate on your bill or with the company. The electricity is usually a small cost compared with the nutrients and the labour, but a bigger pump, or a fan, changes that quickly.

Now plan the backup. A 12-volt battery with a charger and an inverter can run a small air pump for several hours, but check the battery size against the pump rating and the hours of outage you expect. A DWC system with a large oxygen reserve in the water copes with a short outage better than an NFT channel, which dries out within minutes.

• Note the outage pattern in your area for two weeks before you buy.
• Choose a pump rated for the tank size, not the biggest one in the shop.
• Keep one spare air stone and one spare pump in the store.
• Test the battery backup once a month, not only when the power fails.

Our poultry side has the same worry. Our guide to water supply and storage on a poultry farm covers tanks and backup flow, and many of its rules carry over to a hydroponic bench. A flock also needs water through a blackout, so plan the backup for both and keep the bench on its own line, so a fault on one does not drain the other.

Root rot, algae and the warm-water problem

Brown, slimy roots are the classic sign of trouble in a hydroponic system. The usual cause is a warm reservoir with too little oxygen, and a fungus or bacteria that thrives in those conditions moves in. Once the roots are slimed, the plant stops taking up water even though the tank is full, and the leaves wilt in the afternoon.

Prevention is cheaper than treatment. Keep the reservoir in shade, keep the air stone running, and change the solution on schedule rather than waiting for it to smell. Clean the tank and the net pots between cycles with a mild disinfectant that the supplier recommends, rinse thoroughly, and let everything dry before you refill. Dirty tanks carry last cycle's problem into the next.

Algae is the other problem. Green water comes from light reaching the nutrient solution, and it steals nutrients and oxygen. Cover the tank, paint the outside dark or wrap it, and keep the lid tight around the net pots. If the water is already green, drain it, clean the tank and start again, because the algae will not go away while the light still gets in.

Fungus gnats and aphids sometimes appear on the leaves, particularly in the warm months. Yellow sticky traps, clean growing media and sieved, healthy seedlings keep most of them under control. If you spray, use a product registered for the crop in Ghana and follow the waiting period on the label. Your agric extension officer can help you choose the right product for your area.

The daily and weekly routine

A hydroponic bench rewards a short daily visit. Most problems show up as a change in colour, a change in smell or a change in the level of the water, and a farmer who looks every morning sees them early. The routine takes ten minutes once it is part of the day.

Each morning, check the water level and top it up with plain water if needed. Look at the air pump and the stone, and listen for the pump running. Glance at the leaves for wilting, yellowing or spots, and at the roots through the net pot if you can see them. Note the water temperature with a cheap thermometer.

Once a week, measure the pH and the strength of the solution, and record both. Clean any algae from the tank walls and the net pots. Check the fittings for leaks and the battery for charge. Harvest what is ready, and sow or transplant the next batch so the bench never sits empty.

• Check water level and top up with plain water.
• Confirm the air pump or flow pump is running.
• Look at leaves and roots for colour and smell changes.
• Record the water temperature.
• Measure pH and feed strength once a week, and write both down.
• Change the reservoir on schedule, not when it looks bad.
• Harvest on the day the crop is ready, and wash it in clean water.

Selling fresh: who buys and how fast it spoils

Hydroponic leaves are sold on freshness, and freshness is measured in hours. A bunch of basil cut at dawn and delivered by midday is a different product from one that sat in a warm car for a day. Choose buyers within an easy drive of the bench, and plan deliveries around the harvest rather than around the buyer's convenience.

The usual buyers for small hydroponic growers are restaurants and hotels in the nearby town, juice and salad bars, cafés, supermarkets and the grocery shops that stock fresh herbs. Some farmers sell to food sellers and home cooks through direct orders on WhatsApp. Ask each buyer what size bunch or pack they want, how often they order and how they like to be paid, and write the answers into your plan.

Price is the one number you must check for yourself. Market prices for basil, lettuce and herbs change with the season and the city, and a price that worked last year may not work now. Check the current rates at your local market and at the restaurants you plan to supply, and build your plan around what you can sell at a margin you can live with.

Packaging matters too. Clean containers, a label with the crop and the harvest date, and a cool box for the trip all add to the price a buyer will accept. Keep the cold chain simple: harvest early, keep the leaves out of the sun, and deliver the same day.

What a poultry keeper can take from a hydroponic bench

Hydroponics does not use manure directly, and you should never put poultry litter into a nutrient solution. The solids and the bacteria in fresh or partly composted litter clog the system and carry disease into the roots. A hydroponic bench stands apart from the poultry side in that way.

The habits transfer, though. A chick house and a hydroponic bench both live or die on daily checks, clean water, steady temperature and a written record. If you already keep a log for the flock, add a second page for the bench. A farmer who can read one book can read both.

Soil crops next to a poultry house can use the litter. Well-composted poultry litter is a useful fertiliser for the beds, and the method is in our article on using poultry manure as fertiliser. Keep the hydroponic tanks well away from the litter store, and keep the birds away from the tanks entirely.

If the bench grows into a second enterprise, the chicks are still where the flock starts. Our day-old chicks page lists the breeds we hatch, the breed guide helps you pick between them, and the order section takes chick orders. The poultry record keeping guide shows how to keep one notebook across the flock and the crops.

A few growers move from a bench into a protected soil house later. Our article on greenhouse vegetable farming in Ghana covers the site, heat and pest issues that come with that step, and the guide to integrating poultry with crops and fish shows how the enterprises can share labour and manure. Biosecurity matters on both, so keep the routine in our biosecurity guide close at hand.

Checklist for your first season

Work through this list before you buy the full system. Each line is a small decision that prevents a larger failure later in the cycle.

1. Choose one crop that tolerates the season you are starting in.
2. Choose one simple system, usually DWC or Kratky, and build it in the shade.
3. Test the water for pH, conductivity and hardness, and keep the result.
4. Buy the nutrient stocks from a dealer who can show the label and the date.
5. Record the outage pattern in your area and plan a battery or gravity backup.
6. Cover the reservoir to keep light out, and check it stays cool.
7. Set up a daily check and a weekly measurement routine, and write them on the wall.
8. Find two buyers within an hour of the bench before the first harvest.
9. Agree a plan with your agric extension officer for pests in your area.
10. Review the records at the end of the cycle and change one thing before the next.

When the first crop is in, write down what you would do differently. That note is worth more than any guide, because it describes your own water, your own power and your own market.

Questions farmers ask