Rooftop hydroponics

In hydroponics, plants are grown without soil and float in nutrient-rich water. NASA is using hydroponics to provide fresh and healthy food to astronauts on long duration missions. Given that land and water will become increasingly scarce, the movement towards hydroponics is forecasted to get stronger. Hydroponic agriculture uses only about 10% of the water and land required for conventional agriculture. It even enables vertical farming. Akash and Monica are able to grow 1200 heads of lettuce in 70 square metres of their rooftop.

However, hydroponics is not the only thing this entrepreneurial couple does. Akash Heimlich, who was born in Auroville, is a software developer, an embedded system designer, and has a passion for anything related to renewable energy and energy efficiency. In 1997, he founded Cynergy, a software and hardware solutions company. In 2013, he launched their highly popular product, Wattmon, a remote energy monitoring and control solution, which is sold in over 40 countries.

Monica holds degrees in biology and biochemistry from the University of Navarra, Spain. She came to Auroville in 2002 when she was 24 years old. She says, “I worked in about ten jobs in the first two years. I worked in the Health Centre, Botanical Garden, Matrimandir nursery, Aurobrindavan lab, but finally I chose to study graphic design with Suzanne in Lumière.” She now uses her skill in graphic design to help Cynergy in corporate image building.

Monica recalls their beginning years, “Every evening Akash and I would finish with our computers and then we would go into the garden to grow plants.” In Maitreye, every resident was allocated a tiny plot for a garden. And they loved pottering in their tiny garden. Monica says, “The garden was small but required a lot of maintenance. Digging, weeding, watering, putting manure and then, sometimes after weeks of hard work, we would find all the plants eaten up by snails and other pests.” They tried aquaponics (which is a combination of aquaculture and hydroponics) but had to stop it after a cyclone damaged the aquaponic system at Reve.

They read about hydroponics on the internet and were fascinated with this new way of growing plants. And so their garden shifted to the rooftop. Monica continues, “Hydroponics is technically more complicated, but once it is set up, there is almost zero maintenance. And it was fantastic to grow salad without mud. I had a lot of problems before with parasites like amoebas and other microorganisms. But with hydroponics you remove all that, as there is no risk of contamination by parasites in this method.” 

Akash and Monica have visited a number of hydroponic farms in Thailand, Malaysia and Bali. They also met an  agriculture chemist in Thailand who had created her own nutrient mixture formula, and she generously shared this with them. Says Monica, “This formula is working well for us. Professional formulas are more effective and faster but they are also much more expensive.” 

An interesting fact is that the nutrient formula used by Akash and Monica works well when mixed with normal water but does not work well if RO (reverse osmosis) purified water is used (some hydroponic units use only RO water). The conclusion is that normal water has some nutrients which help in plant growth that are missing in RO water. 

Akash explains that the process of growing a hydroponic lettuce starts by putting a seed in a small rockwool cube. Rockwool is a medium to hold the plant and does not  provide any nutrition. For the first 10 to 12 days, these seeds are watered 3 to 4 times a day using an automatic sprinkler system. Then they are shifted to the main grower pipes where the roots dip into a nutrient rich stream of flowing water. The entire cycle to harvesting takes about 40 to 60 days. 

Akash explains, “This whole system is very rudimentary. We started off with a whole bunch of automation and the whole thing ran well for some months, but then it became a bit unstable. And we realized that doing it simply is as good as doing it in a complex manner. It’s a very simple system – we use PVC pipes with holes drilled into them to put the lettuce plant in. There is one single tank at the bottom with nutrient water which circulates with the help of a simple aquarium pump which costs INR 400.”

It may sound simple but their hydroponic system has gone through many tweaks over time. For example, earlier they used coco peat as the growing medium, but it would dissolve and clog the pipes. They also tried fabric and sponge but found pre-cut rockwool to be the best medium. The biggest challenge for them has been the climate in Auroville. They have learnt over time that it is better to stop growing during the extreme heat of the summer months, but they are able to grow lettuce for 8 to 9 months of the year. There are other unusual challenges they have faced. For example, a clever crow which used the plant hole to dip his food in water to make it soggy, and bees which decided to build their beehive on one of the grower pipes. Their latest challenge is dealing with the after effects of the last storm in Auroville which destroyed the plastic sheeting which covers their rooftop. 

While there was initially some resistance to hydroponically-grown vegetables, that has changed now and most Aurovilians appreciate the fresh and juicy lettuces. Currently, they sell their lettuces through the Auroville outlets ‘Bread and Chocolate’ and ‘Hers’.

Monica mentions that they are mainly able to sell lettuce and some rucola. She tried parsley but there was not much demand for it. She also grew spinach but the market was flooded with spinach at the time, so the price was too low. 

But things will change once they have their own hydroponic farm-cum-restaurant. Their idea is to have a salad and sandwich bar on one side, and Monica’s renowned pastries on the other side. Two and a half years ago, Akash and Monica applied to Auroville’s Town Development Council (TDC) for permission to create a hydroponic farm-cum-restaurant. They were thrilled when three months back the TDC finally approved their application. However, there are still some formalities pending, such as site selection and approval.

Hopefully soon Aurovilians will be able to eat healthy salads and then, guilt-free, gorge on Monica’s desserts!