Aquaponics is a method of food production that combines aquaculture, or raising fish, with hydroponics, or growing plants in water, in a contained ecosystem with nothing artificial added. Two classes are taught at the gardens on Sunday, Aug. 25: Aquaponics 1 teaches how to build a system, from 9 a.m. to noon; and Aquaponics 2, a classroom session with take-away materials, covers options for fish, plants, and supplies, from 1 to 4 p.m.; $65 for both classes, $40 for each, includes a 10 percent discount on supplies. Both classes are available both days. Call 326-9686, ext. 10, for reservations and more information.