Nitrogen use efficiency must be considered to reduce environmental pollution and production costs. Among the possible strategies is nitrogen reduction, provided it is not done during the nitrogen-critical growth phase, to avoid decrease in production. This study aims to analyze the effect of different nitrogen concentrations on three critical growth phases and assess the efficiency of nitrogen use in relation to yield. The research was conducted in a hydroponic system in the greenhouse of the Agricultural Development Polytechnic of Malang. The research method used a group randomized design. Treatments consisted of variations of 100% nitrogen concentration as control, 25%, 50%, and 75% nitrogen concentration at three growth phases: vegetative phase (V), pollination and fruit formation phase (PFF), and fruit enlargement and ripening phase (FER). Data were analyzed using ANOVA and (Turkey) test. The results showed that FER-50% treatment resulted in plant height of ±210 cm with optimal growth balance between phases. PFF-75% showed higher total leaf area (±77 dm² plant-1) and total dry weight (±125 g). The chlorophyll index and relative growth rate showed physiological balance as the plants entered the reproductive phase, regardless of variations in nitrogen input. The control treatment (100%) produced fruit weight that was not significantly different from other treatments except V-25%. The FER-25% treatment showed the highest nitrogen use efficiency while maintaining competitive fruit yield. Reducing nitrogen to 75% at the fruit enlargement and ripening phases maintained competitive yields while significantly improving nitrogen use efficiency. This strategy supports optimal productivity and reduces production costs and environmental impacts, supporting the evolution of agricultural practices toward more sustainable systems.