The greenhouse at R-5 High School is humming with life and noise.
Huge fish tanks containing hundreds of baby tilapia bubble and churn as water circulates.
Pumps murmur as they move the fish water into bacterial converters, where microorganisms change the ammonia- laden fish excrement into nitrites and nitrates.
More pumps efficiently move then nutrient-rich water into raised garden beds, where seedlings will grow into lettuce and peas, chard and basil.
By midsummer the greenhouse will produce up to 200 heads of lettuce every week, using the homegrown fish fertilizer, water and little else.
This is aquaponics, a symbiotic system of animals and plants, and it's unique to the R-5 High School.
Aquaponics is not a new concept, said teacher Dustin Giesenhagen, but few schools in the country have created such a large-scale system.
Giesenhagen said the project has taken hold of some students, sparking curiosity and interest.
"It's pretty magical for me, because now as a teacher I get to learn and experiment," he said. "It's less about worrying, 'Are they learning?' We are learning together. I think that's a really cool thing to strive for in education."
The system has a few smaller garden beds where students can experiment with growing different types of fruits and vegetables in a soil-less rock mixture.
The larger deep water culture beds will hold hundreds of heads of lettuce, floating on buoyant boards as their roots grow freely into the nutrient-infused water below.
Senior Mercedes Barrier helps feed the fish and plant fruits and vegetables. Right now she's focused on trying to grow strawberries in the experimental beds.
"When I first heard about it, I thought it was one of the coolest things in the world, to grow plants and grow fish and have it in a contained area using the same water," she said.
The lettuce will either be used in School District 51 cafeterias or sold to the community, Giesenhagen said.
"It's sort of the future of food," he said "Anywhere in the world you could set something like this up and grow food 365 days a year. To have our students have that in their education and not just learn about the future but be a part of what our food future looks like, that's a really powerful thing."