Evaluation of Hydroponic Methods for Cultivation of <i>Gynura procumbens</i> (Longevity Spinach) in an Aquaponic System

ABSTRACT The purpose of this study is to investigate the performance of different types of hydroponic growers on plant growth yield and nutrient uptakes for growing Gynura procumbens (G. procumbens) in an aquaponics system. A backyard‐sized aquaponics unit was realized containing different types of growers, namely media grow beds, deep water culture, and nutrient film technique (vertical and horizontal systems). Experiments were carried out for 8 weeks in which water quality, fish growth, and plant yield were monitored on a weekly basis. Other parameters measured include water temperature, pH, total suspended solids (TSS), and dissolved oxygen (DO) concentration. Water temperature, pH, TSS, and DO concentration values remain within the reasonable limit for growing G. procumbens and culturing hybrid tilapia ( Oreochromis spp.). A high ammonia‐to‐nitrate conversion was achieved for the studied aquaponics system. This indicated that the nitrifying bacteria population in the system was effective in converting ammonia to nitrates. Nitrates are indeed essential in plant growth. It was also found that the highest plant yield was achieved in the deep water culture unit, where G. procumbens grew fourfold higher throughout the 8‐week cultivation period.