2017 ASHS Annual Conference

Aquaponics is an integration of aquaculture and hydroponics – a soilless system for crop production. Water holding and chemical properties of an aquaponic system’s media can be critical in the success of plant and fish production. This experiment consisted of two longbed systems each with three different plant varieties (tomato, bell pepper, and peppermint); each system contains six individual beds with one plant species designated in two beds. One goal of this study was to compare growth parameters of tomato (Solanum lycopersicum) and bell pepper (Capsicum annuum) grown in two separate media types: gravel and lightweight expanded clay aggregate (LECA). Preliminary water tests were conducted before the introduction of the plants into the system. Before the addition of plants into the system, water chemical properties expressed little variation between the two medias. Root fresh and dry weights and total fruit weight were assessed after 12 weeks. Water solution nitrate, nitrite, ammonium, pH, and dissolved oxygen were measured twice a week for 12 weeks. Water pH ranged from 6.0 – 7.6, and ammonium concentrations ranged from 0 – 8.0 ppm. LECA and gravel are viable media sources in aquaponic tomato and pepper production in southern Texas.