The effect of chitosan gels, with and without encapsulated nutrients, on the growth of Solanum lycopersicum (tomato) plants was evaluated under different wavelengths of LED light: green (λ = 525 nm), blue (λ = 450 nm), and red (λ = 730 nm). The study was conducted in a closed, floating-root hydroponic system, analyzing the impact of combining light and microgels on plant development. The results showed that red light significantly promoted seedling growth, with the highest values for fresh weight (248.28 ± 31.51 mg) and stem height (3.65 ± 0.25 cm) when the chitosan gel with NPK (CS-NPK) was used. The results reveal that red light activates phytochromes, promoting stem elongation and biomass accumulation. In contrast, blue light resulted in more intense leaf coloration, and green light showed an intermediate effect on stem biomass and height. The use of nutrient-enriched chitosan gels improved plant development compared to nutrient-free gels.