News You Can Use: Aquaponics

HONOLULU (HawaiiNewsNow) - Aquaponics is the combination of hydroponics and aquaculture.

In this system, everything is recirculated. The tilapia eat fish food and generate metabolites through digestion, which are pumped into the growth tray to provide nutrients for the plants.

"It uses two percent of the water of traditional agriculture because you can see water goes in and comes out but none of it goes in the ground," explains Harry Ako, a professor of molecular biosciences. "What is a toxin for a fish is a nutrient for a plant and so the fish are, actually they're happier with the plants there because the plants help clean up the water."

Through 30 years of teaching and research, Ako has developed an inexpensive yet productive aquaponics system.

"This is the little water pump it's a tiny little thing, but it works. It pumps water from here into the tray and then the excess water overflows and goes back in the fish," Ako says. "To put a system like this together takes maybe two hours."

The system is quick to put together, but you'll want to consider a couple of things. It needs electricity to run and you'll need help setting it up properly.

"It uses a 50 watt air pump, so that's half a light bulb, and it uses a 4 watt water pump so the whole thing is half of a light bulb," Ako says.

"Anyone can do it but everyone needs a little help," adds Sean Short, a student at the University of Hawaii at Manoa. "Get online, look us up and give us a phone call and we're happy to talk story and just help you out."

Systems you find online can cost thousands of dollars, but Dr. Ako says his system costs about $400, which is economical considering the crop tastes so good, they sell at a good price. "Our best guy has one acre and he sells 15,000 heads of lettuce a month."

They grow everything from lettuce to basil, tomatoes, cucumbers, and the tilapia taste good too. In fact, top chefs have served aquaponic tilapia in their restaurants.

Contact Dr. Harry Ako at 956-2012 or email him at for more information.

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