By Vina Medenilla
In metropolitan areas, rooftops are frequently utilized as green spaces by home gardeners. For some people with rooftop gardens, the area serves as a way for the family to bond in a way that connects them with nature amid the busyness of the city.
This is why Gerilen Elinessete together with her husband, both licensed engineers by profession, built their own garden on their rooftop. As a result of their love for planting and DIY projects, they were able to strongly influence their children into growing their own food and eating vegetables.
They do container gardening and operate their own aquaponics system as well. They call it a ‘zero-waste garden’ as the materials used are mostly recycled, including their aquariums and containers.
What is aquaponics?
Aquaponics is derived from the words ‘aquaculture’ and ‘hydroponics.’ It is a combination of two systems: aquaculture, or the raising of aquatic animals, in this case small fish in aquarium tanks, and hydroponics, meaning plant cultivation in water.
Through the aquaponics system, they can harvest leafy vegetables like lettuce in less than a month. They grow lettuce, watercress, and kangkong using the aquaponics system while their tomatoes, spring onions, papaya, ampalaya, alugbati, cilantro, malunggay, and kale are planted in pots.
Items they use are yogurt cups, excess polyvinyl chloride (PVC) pipes from their construction projects, air pump, water pump, and discarded plastic containers like cracked storage boxes, broken water dispensers, and even styrofoam boxes from purchased appliances.
Some fish in their aquarium are goldfish and Siamese algae eaters. They also have some tilapia in a separate aquarium.
They feed the fish with regular fish food like pellets and crushed “apa” flakes (made from fishmeal, vegetable proteins, and binding agents such as wheat flour). They also feed the fish with chopped pechay or lettuce leaves.
They have an air pump in the box where the goldfish are located since the Siamese algae eaters do not need oxygen assistance.
To complete the setup, these are what they’ve prepared to make the hydroponics system:
This pump is used to keep the water circulating throughout the aquaponics system. Through this, the plants are fed with nutrients as the aquarium water is transported to the plants via the air tubes.
They drilled holes into three diameter PVC pipes with a distance of six inches apart using a hole saw. This serves as a holder of the water so the plants will be soaked with the flowing aquarium water.
Pots used are food-grade plastic like yogurt cups, beverage bottles with uniform height, and multivitamins bottles or whatever cups that fit in the pipes’ hole.
To plant the seeds, add pebbles to the yogurt cups or to the chosen container so the plants will have easier access to moving water.
According to Elinessete, crushed or whole eggshells are good additives to the water pump or the aquarium so the plants will have a source of calcium. In designing one’s aquarium, tin cans may be added for fishs’ amusement as well. If algae forms in the pots, push them aside or remove them completely to avoid clogging the aquaponics system. Most importantly, keep adding water to the system, especially during extremely hot weather.
To protect the plants from strong winds during a storm, use a net discarded table cover.
Challenges in rooftop gardening
Birds, strong winds, and direct sunlight are the challenges that the family have encountered in their garden. Elinessete said that some birds eat their plants because they are located outdoors.
Strong winds tend to bend young plants and direct sunlight sometimes kills the fish in the aquarium. To prevent birds and strong winds from destroying the plants, the couple use nets to protect the system. They keep the fish healthy by continuing to add water to the tank, especially on hot days.
Benefits of rooftop gardening
Aside from reusing plastic materials through DIY, Elinessete said that they can harvest and secure their own food. If they are busy with work, what they do with their harvested leaves is wash them and put them on top of steaming rice.
Through having access to available food in the garden 24/7, they are able to cut down on their grocery expenses. For instance, as the Enhanced Community Quarantine continues, they do not have to go out and buy P180 per kilo-priced calamansi in the market as their garden provides them with calamansi which they can serve anytime.
Gardening is proven to hold emotional benefits. For Elinessete, this does not only keep her away from stress but she said that it is also a great form of exercise when she goes up and down on her way to their rooftop garden while carrying gardening equipment.
The best part of gardening for the couple as parents of two is that their children benefit from the activities they do in their garden. Because of their influence, their kids love planting and eating vegetables fresh from their rooftop.
Photos from Gerilen Elinessete