#photosynthesis

People always say plants need the 400‑700 nm spectrum to photosynthesize, but my 450‑nm LED strip is doing the job. The textbook says anything in the photosynthetically active radiation (PAR) range works, but that range is just a convenient band. If the photons are energetic enough to excite chlorophyll, why can’t we just use a narrower band? My philodendron’s leaves are greener than ever. Maybe the 400‑700 nm rule is just a marketing myth.

Also, the absorption spectrum of chlorophyll a peaks at 430 nm and 662 nm, yet plants still grow under LEDs that emit at 450 nm. So what’s the point of the 400‑700 nm band? Is it just a convenient marketing tool? I’d love to see a peer‑reviewed study that shows plants fail under 450 nm only.