## 3 Discussion
Future studies should continuously monitor the concentrations of minerals in the aquaponics system to establish the efficiency of nutrient cycling. When compared with aquaponic and field-collected plants, hydroponic plants had a higher polyphenol content; however, there were no significant differences among the treatments. Plants in the hydroponics yielded a considerably higher total flavonol content than the aquaponic plants and field plants, but they were also not significantly different. Broadly, these results demonstrate that aquaponics and hydroponics perform equally, oreven better in the case of hydroponics, than field-cultivated plants. Research has revealed that nutrient availability can significantly influence plants' secondary metabolism and antioxidant activity [46]. While in the current study, the high levels of Cu, Zn, and Mn in aquaponics did not positively influence the secondary metabolites, the hydroponic plants had higher N, P, and Mg, and higher flavonoid contents. Previously, it has been demonstrated that these macronutrients in higher levels influence secondary metabolite production. For example, [PERSON] et al. (2010) [47] reported that nitrogen levels significantly affected the production of total phenolics and flavonoids in _Labisia pumila_ Benth. ; total phenolics and flavonoids were reduced with increased concentration increased progressively. The essential oil profiles of _H. odoratissimum_ have been studied extensively, revealing that these species produce a complex bouquet of vegetative and floral volatiles [48]. Several essential oil products derived from _Helichrysum sp_. are available for medical and non-medicinal uses on the market commercially. Although there was no statistical difference in the total number of volatile constituents in the three cultivation strategies, it is worth mentioning that alpha-terpineol, a potent antioxidant and antifungal agent, occurred in higher concentrations in the aquaponic plants [49; 50]. Alpha-terpineol can cause leakage of the cytoplasm and serious hyphae distortions and spore disruptions in _Aspergillus ochracaeus_[51; 52]. They are used as a pesticide substitute in plants because of their safety and efficiency. Other important compounds that occurred in significantly higher levels in aquaponic plants than in the hydroponic and field-collected plants included alpha-phellandrene, o-ethyltoluene, tetradecane, alpha-curcumene, and palustrol. Alpha-curcumene, isolated from the fresh aerial parts of _Senecio selloi_ Spreng. DC, had high antifungal activity against _Enterobacter cloace_[53]. In previous research, monoterpenes and sesquiterpenes. Generally, monoterpene and sesquiterpene hydrocarbons dominated the essential oil of _H. odoratissimum_. Monoterpenes, sesquiterpenes, and diterpenes are some of the broad groups of compounds present in the essential oils of most plants, including the _Helichrysum_ genus; these compounds are primarily responsible for the reported antifungal, antibacterial, antidiabetic, anti-inflammatory, antiulcer, anticancer, antioxidant, antinociceptive, and antispasmodic properties associated with these plants [54]. The beauty and pharmaceutical industries extensively use alpha-terpineol (-terpineol), a monoterenoid alcohol which was also confirmed in this study [55]. Another significant sesquiterpene found in a variety of plant essential oils known as beta-caryophyllene has been linked to several significant pharmacological effects, including immune-modulating, anti-inflammatory, anti-cancer, cardioprotective, hepatocyte, gastroprotective, and renal protective effects [56]. Interestingly, the same compound was confirmed in the current study. The antioxidant capacity of leaves from _H. odoratissimum_ cultivated via hydroponics was significantly higher (_p_ < 0.05; ABTS) than plants grown in the field. Although the higher antioxidant activities were produced by hydroponic plants than aquaponic plants, the differences were not significant.