David Githanga is busy man, as busy as any doctor.
The pediatrician and cardiologist does not just treat. He has undertaken to educate mothers and expectant women on proper child nutrition. And because nutrition is dear to his heart, he has undertaken to produce a rare and relatively unknown food to help boost immune system in children, the elderly people living with HIV/AIDs
Every weekend, and whenever he is free, he drives with his wife Dr Jessie Githanga to their Gilgil farm where they grow spirulina.
Spirulina is a type of algae with high-value food supplement, sold in health food stores as dried powder, tablets and capsules. Health experts say it contains a unique element, phycocyanin (‘algae-blue’), known for boosting the immune system, detoxification and anti-ageing properties.
Dr Githanga says he was inspired to establish a spirulina farm by his profession, which instilled in him the desire to help boost the immune system of infants.
“It is heartbreaking to receive patients with deteriorated health conditions which can be prevented through proper feeding. I decided to grow this crop to provide a solution to people with low immunity,” Dr Githanga tells Smart Harvest at his farm.
The pediatrician says spirulina is a super-concentrated nutrient source. The crop contains about 65 per cent complete protein, anti-oxidants, essential omega-3 fatty acids and other compounds with healthful anti-inflammatory, anti-viral, and anti-cancer properties.
To provide conducive conditions for the crop, he established a greenhouse measuring 19.5 metres by 7.8 metres for the aquatic crop.
Inside the greenhouse are 12 cemented troughs measuring six metres by one metre each where the crop is planted.
The greenhouse is installed with gutters to harvest rain water, which is then channeled into a tank. “Rain water is the best in spirulina farming because it has no chemicals like water sourced from rivers and dams,” he says.
When starting the venture, he bought five litres of substrate (seeds) from Masinde Muliro University of Science and Technology at Sh1,000 each. He was also trained by specialists from the university on how to produce quality yields.
He then placed water in one trough and fed it with the substrate before embarking on a multiplication process that entails adding salt, water and substrate.
When the first trough proved successful, he decided to increase them to six.
Harvesting is done every day once a pond is full and thick with spirulina.
“Seven days after planting, the crop was thick enough for harvesting,” says the farmer.
To reap maximum yields, the spirulina crop is turned over every two hours to break its long strings into smaller pieces for faster growth. This is done through a process called agitation.
Agitation also helps in aeration for quick germination and prevents the crop from dying. Whenever the strings are left hanging on top of the water, they easily die.
“If the crop is left to concentrate on the top layer, it can easily dry and die,” says Githanga.
To ensure yields production is high, the farmer keeps monitoring the water pH. The recommended pH is between eight and nine.
Adding salt to water improves nitrogen that helps make the crop greener.
“Spirulina is an extremophile, capable of growing in extremely alkaline water inhospitable to almost every other organism compared to other algae that grow in essentially pH neutral water that supports growth of a vast range of algae including those that produce toxins,” says the doctor.
The highest standards of cleanness are essential in spirunila production, since the crop must be kept pure and free of contamination. The troughs are disinfected with jik and spirit to kill germs.
During harvesting, the farmer uses a piece of net to separate the crop from water. Freshly harvested crop is thick, normally 99.9 per cent of water. The crop must then be dried to reduce the moisture content.
“Spirulina cells are tiny, rough, spherical and difficult to pull out of water,” says the doctor.
The harvested crop is placed on a drying trough where it takes at least two days for it to dry. It is then crushed into powder and packaged for sale.
Dr Gathanga says the crop should be eaten or refrigerated within an hour of harvesting. It can stay fresh for three days in normal room temperature but longer when frozen.
When dried, the crop can last for a year. Its shelf-life is also boosted if kept in an airtight container.
From the greenhouse, Githanga harvests at least 360 grammes of dried spirulina every day.
He sells the dried crop to individual consumers and pharmaceuticals. A kilogramme sells for at least Sh6,000.
As harvesting is done daily, spirunila farming requires proper management to replenish harvested crop. A farmer only requires enough starter mix to renew his culture once every six months before he drains the troughs and refills new substrates.
“A farmer has to have technical knowledge on how to ensure a quality product is harvested,” says the pediatrician.
Each time the crop is harvested, a little make-up -- salt, alkaline and nitrogen -- is added to replenish the nutrients taken out in the harvested spirulina.
“The proper amount of make-up mix is added back to the troughs as a way of maintaining nutrient balance. The process can be maintained for a high level of growth for about six months at which point the pH will have become too high for the crop,” says the farmer.
Farmers can keep spirulina alive by slowing down their metabolism through lowering temperature.
Dr Githanga says his main challenge is lack of market because most Kenyans do not know the crop or its health benefits.
Labor intensity is also another challenge facing production of algae like crop because for multiplication, agitation is required after every two hours.
“My joy is seeing people live happily and free of diseases. This is the reason I am planning to woo more farmers into spirulina,” he says.