Aquaponics farming: How two hotels are looking to boost their sustainable practices
Chef Robert Stirrup and gardener James Lam are involved in the day-to-day operations of the aquaponics farm, capable of producing up to 1,200 kg of vegetables and 350 kg of fish monthly. (Photo: Try Sutrisno Foo)
SINGAPORE: You're sitting down in a restaurant with some friends, looking at the menu of finely curated steaks, fish dishes and salads.
The ingredients for these dishes would likely come from countries like New Zealand, Indonesia and Malaysia. This is given that Singapore imports most of its food.
But for guests at the Fairmont Singapore and Swissotel The Stamford, some of the ingredients could come from a place much closer - the hotels' rooftop, where an aquaponics farm was recently installed.
Aquaponics is a combination of aquaculture and hydroponics, where fish and plants are grown together in a closed system.
“Quite simply, you feed the fish, the fish eat the food, pass the food, and then all the nitrates from that go through the different towers and the different beds within the garden.
“The vegetables absorb the nitrates from the water, and grow, in a circular system,” said chef Robert Stirrup, who is also the director of culinary operations at the hotels. He oversees the farm’s daily operations.
The hotels said the farm will be able to produce about 1,200 kg of vegetables and 350 kg of fish monthly for the hotels' kitchens once it's fully operational.
The farm is the brainchild of the hotels' general manager Marcus Hanna.
“I was at a friend’s place for dinner, and he had this hydroponics tower in this living room, where he was growing numerous types of lettuce. I was quite intrigued by that, because as you know, 90 per cent of the produce in Singapore is imported, so to have something in the living room – you’re not going to find anything fresher to eat,” he said.
He wanted to replicate this freshness for the hotels' guests, and raised the idea with Mr Stirrup and Mr Ahmed Disokey, the area director of technology and business innovation at Accor Luxury Hotels. The Accor Group operates both hotels.
They bought into the idea quickly as it will also boost the hotels' sustainability efforts and four months later, they had turned it into an operational aquaponics set-up.
READ: Raising the roof: Cultivating Singapore's urban farming scheme
THE CHALLENGES TO OVERCOME
Nestled between the hotels' two buildings, the 450 sq m rooftop farm is deceptively small.
Yet, that's enough space for thousands of leafy vegetables - from kangkong (water spinach) to several kinds of lettuce - to grow on two rows of densely packed white towers and six rows of green plastic half-cylinders, also known as module infinity tanks (MITs).
Five fish tanks in the back, each containing about 400 little red tilapias, complete the system.
In 10 months' time, the farm will produce 30 per cent and 10 per cent of the hotel’s daily requirement for greens and fish respectively, estimated Mr Hanna.
Two gardeners perform the day-to-day maintenance.
“It’s very difficult to sustain something up here under this kind of conditions.
“We don’t have enough light, we don’t have enough sunshine, we don’t have water, we have extremely strong winds coming through. So this is not a very ideal location,” said Mr James Lam who was hired about five years ago to tend to a tiny herb garden which used to occupy the space.
There is also the issue of regulating the temperature and moisture in the farm, said Mr Stirrup.
“We had to work out a way of dropping the temperature so we put the tentage and the coverage over the aquaponics itself and it helps us to bring the temperature down by about six degrees which makes it more of an ultimate temperature to grow a lot of those vegetables,” he said.
HOW THE PRODUCE ARE GROWN
The farm is outfitted with features that provides an optimum environment for the plants to grow rapidly – a shelter protects the plants from direct sunlight and cools the area to between 24 and 25 degrees Celsius during the day.
LED lights hung above the plants are switched on from 6pm to 8pm to boost their growth.
They help shave off 50 to 60 per cent of the time needed to grow the vegetables, said Mr Disokey.
Fast-growing vegetables and fish are grown in different batches for a constant supply of produce. A collection of herbs completes the farm.
“We have one of the largest collection of mints,” said Mr Lam, counting them off on his fingers. Some choice mints include: chocolate, pineapple, ginger, orange, lime, grapefruit and apple, which are specially curated for use in the hotels' bars.
The gardeners work closely with the chefs in the kitchen so that what is grown is tailored to their needs.
Describing how vegetables are grown on the aquaponics system, Mr Lam said the seeds have to be individually placed into a floating block by hand. Sometimes he and fellow gardener, Ms Jenny Kang, will put two seeds into the same cross-shaped opening as an assurance that at least one of them will grow. Each block contains between 60 and 96 such openings, depending on its size.
These blocks will go into the nursery for one to two weeks, until the seeds germinate. They would then be transferred into individual pots and are left to grow either in the green MITs or towers. The vegetables would take three to four weeks to be fully grown.
The hotels are looking to incorporate them in special menus in several of their restaurants.
“The idea will be that we will do dishes on the menus where we will use initially… the vegetables, and then long-term, the idea is obviously we will incorporate the fish into the dish, so we will have a completely sustainable dish from the garden,” said Mr Stirrup.
While the farm can only produce 30 per cent of all vegetables needed, Mr Stirrup is optimistic that in time it will be able to produce enough of some varieties to fully meet their requirements.
The hotels are also hoping to experiment with growing fruits including a variety of strawberries which have grown well in Thailand.
“Just working through the whole process, to actually see what vegetables work well and grow in the best way, that we would shorten it down to the products that we would select long-term,” said Mr Stirrup.
To see the farm grow from an idea to a reality is “very exciting”, he added.
“I’ve only seen this done on a very small scale within a hotel before. Not as aquaponics, but as hydroponics.
“So for us to actually build on the scale that it is, to see it actually being very close to where we can actually go to pick and use it, and to actually just taste some of the product and how fresh it is, in comparison to some of those products that we’ve been buying… it’s very different.”
'30 BY 30' VISION
The aquaponics farm is the hotels' way of helping Singapore attain its '30 by 30' vision, said Mr Hanna.
Announced in March this year, this is a target set by the Singapore Food Agency (SFA) for the country to produce 30 per cent of its own nutritional needs by 2030.
Aquaponics is only one prong of the hotels' sustainability drive.
There are several initiatives, among which are: the Eco-Wizz digester, which turns leftover food into water and compost; the Treatsure App, which sells the buffet food at reduced prices just before closing; and a partnership with local charity ‘Food from the Heart’ which collects leftover food from the hotel to support families in need.
As a champion of several sustainability initiatives, Mr Stirrup is extremely conscious of the impact of the efforts in promoting sustainability.
“Honestly, we have a huge impact, being such a big property, on the volumes and quantities that we use. So even making a small change… obviously has a huge impact on how much we’re actually producing in terms of waste and what can be recyclable instead,” he said.
