Bacteria in the plant beds help convert the ammonia from the fish waste into nutrients for the plants. This process filters out the fish waste, resulting in clean water which is then pumped back into the fish tanks. This is one of the coolest things about Aquaponics, that it mimics a natural ecosystem. Aquaponics represents the relationship between water, aquatic life, bacteria, nutrient dynamics, and plants which grow together in waterways all over the world.
"It’s like our tomato plants serve the same function as a filter in a home aquarium," Brannström explains. "And in the time it takes a fish to grow to about one kilogramme, you can produce about 10 kilos of tomatoes."
With recently added capacity, Peckas facilities can produce up to 400 tonnes of vegetables and 40 tonnes of fish annually. Gas is also a critical component of Peckas’ aquaponics solution. While the fish produce carbon dioxide naturally, levels aren’t high enough to optimize plant growth. Thus, CO2 supplied by Linde is pumped into the greenhouses, doubling levels from around 450 ppm to between 800 and 1,000 ppm.
"Carbon dioxide is an extremely important ingredient for the whole process," explains Brannström. "It creates ideal conditions for growing tomatoes and other plants. You end up with substantially higher yields." Greenhouses are also a practical way to take CO2 out of the atmosphere instead of burying excess carbon dioxide underground. "It’s better to build more greenhouses and let plants consume CO2," he says.