Tilapia glide through a blue, 300-gallon fish tank inside what used to be a small office at George Mason High School. The students raising the fish eventually hope to have enough for taco lunches — and a few left over to sell to local restaurants.

Elsewhere, in a dim, converted employee break room in the Falls Church, Va., school, recently planted seedlings peek from small squares cut into plastic flats. A small reservoir below feeds water mixed with nutrients to the plants. LED lights hang above.

In about 40 days, the plants will bloom into leafy heads of lettuce — butterhead, red summer crisp and red oak leaf. Cafeteria employees will harvest the crop, walk a few steps to the school’s industrial kitchen, and prepare the lettuce for sandwiches and the lunchtime salad bar.

Call it the high school version of farm-to-table — the farm being any space that can be spared inside the roughly 800-student school. Last year, students cultivated more than 85 pounds of lettuce that helped provide fresh, healthy meals at the school, said Richard Kane, the district’s food service director.

A huge farm isn’t needed, Kane said. “We’re actually doing it indoors, utilizing space that we already have,” said Kane, who pays the student club $2.86 a pound for the lettuce, the same he would a vendor.

And people are taking notice: In June, the Environmental Protection Agency awarded the high school students a President’s Environmental Youth Award for developing healthy and sustainable farming practices.

It all began, as these things often do, with a seed of an idea — and a grant.

A dozen students last school year embarked on a project involving something called hydroponics — the process of growing plants without soil. They received a $16,000 grant from the Falls Church Education Foundation, which raises money for schools, said Peter Mecca, a science teacher who oversees the students.

Five hydroponics systems are set up between the high school and a neighboring middle school.

The George Mason students built on their farming efforts by beginning an aquaculture project, raising fish in a tank, this year. Ultimately, they want to use water from the tilapia tank to provide nutrients for the plants — aquaponics.

“We’re constantly increasing our effort to do things,” Mecca said.

The students have experienced a payoff beyond the recognition from the EPA.

For Marjorie Lopez, a senior at the school, the project has introduced her to possible careers that will allow her to make use of her hands.

“I don’t want to grow up to do something in an office all day long,” she said.

Adrian Kamel, an 18-year-old extrovert, has witnessed his shy, quieter peers open up.

“We really didn’t think any of this was going to get as big as it did . . . not only upping what we’re doing here but everyone’s social activity,” Kamel said.

The group’s ambitions are grander, said Kane, the food service director.

Up next: robotic farming equipment that would tend outdoor garden beds at the school.