Taking into consideration climate change scenarios, marine contamination, and a constantly expanding world population, seaweed aquaculture has become an important option for the large-scale production of high-quality biomass. Due to existing biological knowledge of Gracilaria chilensis, several cultivation strategies have been established for obtaining diverse biomolecules (lipids, fatty acids, pigments, among others) with nutraceutical properties. In this research, indoor and outdoor cultivation methodologies were applied to generate high biomass of G. chilensis with positive quality for productive purposes, where the quality was determined according to the concentrations of lipoperoxides and phenolic compounds and the total antioxidant capacity (TAC). The results showed that G. chilensis cultures, which were fertilized for three weeks with Basfoliar® Aktiv (BF) at concentrations of 0.05–1% v/v, obtained high biomass (1–1.3 kg m–2) and DGR (0.35–4.66% d–1), low lipoperoxides (0.5–2.8 µmol g–1 DT), and high phenolic compounds (0.4–0.92 µ eq. GA g–1 FT) and TAC (5–7.5 nmol eq. TROLOX g–1 FT) as compared with other culture media. Lower stress was determined under indoor cultures, due to the operative control of diverse physicochemical stressor parameters (T°, light intensity, photoperiod, among others). Therefore, the cultures developed allow scaling the biomass in productive terms and are suitable for obtaining compounds of interest.