The red channel (620–660 nm) boosts PAR and accelerates photosynthesis; it tightens growth form, triggers pigmentation, and increases CO₂–fertilizer demand. Without proper balance, algae risk rises.

In RGBW aquarium lighting, the blue channel shapes plant form more than growth speed. Leaf thickness, internode length, compact structure, and pigment activation shift with blue intensity. This article covers blue wavelength bands, its relationship with PAR, low/high usage scenarios, and its effects on anthocyanins and nutrient demand.

An overview of the fundamental lighting principles for soft coral reef aquariums, focusing on spectral distribution, blue dominance, and appropriate PAR ranges.