Waiter, There's Koi Fish Waste in My Lettuce
22.09.11
In a 5,000-gallon fish tank in a 1980s greenhouse off a side terrace near Fred Jackson Boulevard, about a thousand koi fish, the fish so often found in Japanese garden ponds, are diligent growing lettuce.
The “tank” is actually an uncovered, down in the mouth-tiled, above-ground swimming pool that local fundamental farmer Pilar Reber purchased at Target about nine months ago. To see the fish plainly, though, you have to walk on tip-toe to the pool’s edge because the koi are, well, coy. They sense the vibrations when a yourself walks toward the pool, and they dive from the surface on approach.
“They’re bonny shy — they used to be more friendly when they were younger,” Reber said.
The foot-eat one's heart out fish, which Reber ordered from farms in Florida and Barstow, Calif. when they were a moment ago about an inch long, exhale ammonia — it’s their wasting product. Then, bacteria that Reber has grown in the koi fish tank convert that ammonia into nitrate. And nitrate is a lettuce fertilizer.
Source: The Bay Citizen